• Mycobiology
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• v.40 no.1
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• pp.82-84
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• 2012

The tulip tree ($Liriodendron$ $chinense$) has been widely cultivated in Korea as a street or garden tree for its large flowers, which have a superficial resemblance to tulips. Occurrence of anthracnose disease on the leaves of tulip trees growing on the campus of Gyeongsang National University, Jinju, Korea, has been observed. Based on mycological characteristics, pathogenicity, and internal transcribed spacer sequence, the causal fungus was identified as $Colletotrichum$ $gloeosporioides$. This is the first report on anthracnose disease caused by $C.$ $gloeosporioides$ on tulip trees in Korea.

• Journal of Korean Society of Forest Science
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• v.77 no.1
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• pp.109-115
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• 1988

Decrease of the planting area reduced fertilized area of forest. To accomplish the aims of natural regeneration, mini-rotation plantation, diminishing the rotation length, maintaining healthy forest and production of good quality timber, forest fertilization should be continued. In order to improve the deteriorate situation, slow-release fertilizer applied on top soil needs to be developed and aerial application will give diminished cost. Fertilization with tending before tree felling in forest will increase the effect of fertilizer more, Proper quantity of fertilizer by tree species and soil fertility should be found out in the future, Street trees, environmental forest near city and ornamental trees in the residential areas could be also included in this field.

• Proceedings of the Korean Society for Quality Management Conference
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• 2007.04a
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• pp.356-358
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• 2007

There are some kinds of greenfield in city. Greenfield is very important about cleaning air pollution. A green field is consist of street-trees, parks, river etc. Plants of greenfield normally take in carbon dioxide and exchange it for oxygen and water vapor; it now appears that plants can also take in other, more dangerous gases, through the tiny openings, or stomates, on their leaves. It is calculated the quantity of taking $CO_{2}$, and emission of $O_{2}$ and We analyse the economic effect about that in this paper.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.2
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• pp.68-81
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• 2023

This study aims to establish a scenario based on the spacing and arrangement of the roadside trees to reduce heat waves and fine dust in cities that occurred during the urbanization process and to quantitatively analyze the degree of reduction. The ENVI-met 5.0.2v model, a micro-climate simulation program, was used to analyze the degree of improvement in the thermal environment and fine dust according to the roadside tree scenario. As a result of temperature analysis according to street tree spacing, the narrower the distance between roadside trees, the lower the temperature during the day as the number of planted trees increased, and a similar pattern was shown regardless of the distance between roadside trees in the morning and evening. In the case of fine dust emitted from the road, the concentration of fine dust increased slightly due to the increase in roadside trees, but the concentration of sidewalks where people walk increased slightly or there was no difference because of blocking fine dust on trees. The temperature according to the arrangement of street trees tended to decrease as the number of planted trees increased as the arrangement increased. However, not only the amount of trees but also the crown projected area was judged to have a significant impact on the temperature reduction because the temperature reduction was greater in the scenario of planting the same amount of trees and widening the interval of arrangement. In terms of the arrangement, the fine dust concentration showed a difference from the results according to the interval, suggesting that the fine dust concentration may change depending on the relationship between the main wind direction and the tree planting direction. By quantitatively analyzing the degree of thermal environment and fine dust improvement caused by roadside trees, this study is expected to promote policies and projects to improve the roadside environment efficiently, such as a basic plan for roadside trees and a project for wind corridor forests.

• Journal of Korean Society of Forest Science
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• v.109 no.1
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• pp.50-61
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• 2020

Street trees are very important to urban environments as they can alleviate air pollution. However, when ozone is absorbed through the stomata, it can induce the formation of free radicals inside the tree, negatively affecting the vegetation. The present study investigated the Air Pollution Tolerance Index (APTI) of four major street tree species: Prunus yedoensis, Zelkova serrata, Chionanthus retusus, and Pinus densiflora. Two-year-old seedlings were placed in a phytotron and fumigated with 100 nL·L^-1 (ppb) ozone for 4 weeks, following which the ascorbic acid contents, chlorophyll contents, leaf pHs, and relative water contents were measured. There was no significant difference in the APTI of Prunus yedoensis and Zelkova serrata between the ozone and control treatments. By contrast, the ozone treatment caused the APTI of Chionanthus retusus to increase and that of Pinus densiflora to decrease compared with the respective controls. These results suggest that the APTI of these tree species exhibit very different responses to ozone. Therefore, more detailed research should be conducted on a range of species in the future.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.2
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• pp.38-53
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• 1998

This study quantified annual net carbon uptake by urban landscape trees and provided equations to estimate it for Ginkgo biloba, platanus occidentalis, Zelkova serrata and Acer palmatum, based on measurement of exchange rate for two years growing seasons from Sep., 1995 to Aug., 1997. The carbon uptake was significantly influenced by photosynthetic capacity, photon flux density and pruning. Ginkgo biloba showed the highest rate of net CO\sub 2\ uptake per unit leaf area and Acer palmatum did the lowest rate among those species. A tree shaded by adjacent building over the growing seasons showed net CO\sub2\ uptake per unit leaf area much lower than another tree of the same species less shaded. Annual net carbon uptake per tree was 19kg for Zelkova serrata, but only 1 kg for Ginkgo biloba and Platanus occidentalis with crown volume dwarfed from pruning. One Zekoval serrata tree annually offset carbon emission from consumption of about 32 liter of gasoline or 83 kWh of electricity. Strategies to improve CO\sub 2\ uptake by urban landscape trees include planting of species with high potosynthetic capacity, sunlight-guaranteed road and building layout for street trees, planting of shade-tolerant species in the north of buildings, and relocation of utility lines to underground and minimized pruning.

• Korean Institute of Interior Design Journal
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• v.26 no.5
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• pp.65-74
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• 2017

The purpose of this research is to analyze characteristics of street elements when pedestrians have a view in the street. The research was utilized eye-tracking experiment and two times survey before and after experiment. The experiment is composed as follows. The data collection was conducted two days period from March 30 to 31, 2017. There were 43 participants who were all male and undergraduate students. In the data recording, the stimulus image was presented 65 seconds on a 23-inch monitor. Prior to analyzing data, the images were represented into five elements of AOI(area of interest). The fixation rate was divided by a period such as 'fixation time' and 'fixation count' parameters. The results were additionally obtained by linking analysis with the area ratio of AOI, time series analysis, and questionnaire. First of all, both building signs and advertisement standing boards draws attentions in participants. From a comparison between fixation rate and survey, the data have negative perspective view. Second, the advertisement standing boards are more eye-catching than other elements regardless of AOI size. It shows the priority of elements what should be developed in the environment. Third, the pavement is rarely seen in the fixation rate. Fourth, the trees are not a long frequency but viewed as a positive element. People want to keep the natural site in the street. In summative research, this method of extracting eye movement data would be provided a foundation data for developing streetscape plan based on scientific factors.

• Spatial Information Research
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• v.21 no.4
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• pp.63-70
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• 2013

With the increasing use of high-performance mobile devices such as smartphones, users have been able to connect to the Internet anywhere, anytime, so that Location Based Services(LBSes) have been popular among the users in order to obtain personalized information associated with their locations. The services have advanced to provide the information realistically and intuitively by adopting Augmented Reality(AR) technology, where the technology utilizes various sensors embedded in the mobile devices. However, the services have inherent problems due to the small screen size of the mobile devices and the complexity of the real world environment. Overlapping contents on a small screen and user's possible movement should be taken into consideration in displaying the icons on objects that block user's environment such as trees and buildings. The problems mainly happen when the services use only user's location and sensor data to calculate the position of the displayed information. In order to solve the problems, this paper proposes a method that applies street data extracted from a digital map. The method uses the street data as well as the location and direction data to determine contents that are placed on both sides of a virtual street which augments the real street. With scrolling the virtual street, which means a virtual movement, some information far away from the location of the user can be identified without user's actual movement. Also the proposed method is implemented for region "Aenigol", and the efficiency and usefulness of the method is verified.

• Asian Journal of Atmospheric Environment
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• v.11 no.1
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• pp.29-32
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• 2017

Ozone concentration in Tokyo Metropolitan area is one of the most serious issues of the local air quality. Tropospheric ozone is formed by radical reaction including volatile organic compound (VOC) and nitrogen oxides ($NO_x$). Reduction of the emission of reactive VOC is a key to reducing ozone concentrations. VOC is emitted from anthropogenic sources and also from vegetation (biogenic VOC or BVOC). BVOC also forms ozone through $NO_x$ and radical reactions. Especially, in urban area, the BVOC is emitted into the atmosphere with high $NO_x$ concentration. Therefore, trees bordering streets and green spaces in urban area may contribute to tropospheric ozone. On the other hand, not all trees emit BVOC which will produce ozone locally. In this study, BVOC emissions have been investigated (terpenoids: isoprene, monoterpenes, sesquiterpenes) for 29 tree species. Eleven in the 29 species were tree species that did not emit BVOCs. Three in 12 cultivars for future planting (25 %) were found to emit no terpenoid BVOCs. Eight in 17 commonly planted trees (47%) were found to emit no terpenoid BVOC. Lower-emitting species have many advantages for urban planting. Therefore, further investigation is required to find the species which do not emit terpenoid BVOC. Emission of reactive BVOC should be added into guideline for the urban planting to prevent the creation of sources of ozone. It is desirable that species with no reactive BVOC emission are planted along urban streets and green areas in urban areas, such as Tokyo.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.3
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• pp.25-34
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• 2002

The purpose of this paper is to discuss the function of microclimate amelioration of urban trees regarding the environmental benefits of street trees in summer, focusing on the heat pollution-urban heat island, tropical climate day's phenomenon and air pollution. We measured the diurnal variation of air/ground temperatures and humidity within the vegetation canopy with the meteorological tower observation system. Summertime air temperatures within the vegetation canopy layer were 1-2$^{\circ}C$ cooler than in places with no vegetation. Due to lack of evaporation, the ground surface temperatures of footpaths were, at a midafternoon maximum, 8$^{\circ}C$ hotter than those under trees. This means that heat flows from a place with no vegetation to a vegetation canopy layer during the daytime. The heat is consumed as a evaporation latent heat. These results suggest that the extension of vegetation canopy bring about a more pleasant urban climate. Diurnal variation of air/ground temperatures and humidity within the vegetation canopy were measured with the meteorological tower observation system. According to the findings, summertime air temperatures under a vegetation canopy layer were 1-2$^{\circ}C$ cooler than places with no vegetation. Due mainly to lack of evaporation the ground surface temperature of footpaths were up to 8$^{\circ}C$ hotter than under trees during mid-afternoon. This means that heat flows from a place where there is no vegetation to another place where there is a vegetation canopy layer during the daytime. Through the energy redistribution analysis, we ascertain that the major part of solar radiation reaching the vegetation cover is consumed as a evaporation latent heat. This result suggests that the expansion of vegetation cover creates a more pleasant urban climate through the cooling effect in summer. Vegetation plays an important role because of its special properties with energy balance. Depended on their evapotranspiration, vegetation cover and water surfaces diminish the peaks of temperature during the day. The skill to make the best use of the vegetation effect in urban areas is a very important planning device to optimize urban climate. Numerical simulation study to examine the vegetation effects on urban climate will be published in our next research paper.