• Title/Summary/Keyword: tree shade

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A Study on Air Temperature Reduction Effect and the Functional Improvement of Street Green Areas in Seoul, Korea (서울 도심 가로수 및 가로녹지의 기온 저감 효과와 기능 향상 연구)

  • Jung, Hee-Eun;Han, Bong-Ho;Kwak, Jeong-In
    • 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.

An Analysis of Thermal Comforts for Pedestrians by WBGT Measurement on the Urban Street Greens (도심 가로 녹음의 습구흑구온도(WBGT) 측정을 통한 보행자 열쾌적성 효과 분석)

  • Ahn, Tong-Mahn;Lee, Jae-Won;Kim, Bo-Ram;Yoon, Ho-Seon;Son, Seung-Woo;Choi, Yoo;Lee, Na-Rae;Lee, Ji-Young;Kim, Hae-Ryung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.41 no.3
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    • pp.22-30
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    • 2013
  • This study aims to measure the thermal comfort effects of urban street trees. As the usual dry bulb air temperature does not indicate properly how the average pedestrian feels the heat of a typical summer day under the strong sunshine, we adopted the Wet Bulb Globe Temperature(WBGT). WBGT involves black globe temperature to measure the direct radiation of sun beams on our bodies, for example our heads. We measured temperatures on very sunny and hot summer days, August 3, 4, and 7, 2012, on the urban streets of Seoul, Korea. Wet bulb, globe, and dry bulb temperatures were measured under direct sunlight from 1 O'clock to 5 O'clock pm. Globe and dry bulb temperatures were measured under street tree shades nearby during the same hours. Then the WBGTs were calculated with the formulae, one for sunny outdoor spaces, and the other for shaded outdoor spaces or indoor. The results are compared with the Korean Standards Association(KS A ISO 7243). The major findings were: 1) On very sunny and hot summer days in Seoul, street tree shades lower the WBGT about 1 to 4 degrees, 2) during the hours of 3 and 4 O'clock in the afternoon, the WBGT under the tree shades are about 3 to 4 degrees lower compared to those under sunshines(approx. 29 to 32 degrees respectively), 3) This difference makes a major thermal comfort for urban pedestrians because senior citizens or weak persons are recommended to move indoor, and even healthy people are recommended stop outdoor sports and take rests in the shades when WBGT is about 32. On the other hand, if the WBGT is around 29, or 3 degrees lower, slower walking, light works or sports are allowable, 4) On site questionnaire survey confirms the thermal comforts under the tree shades, and we even could not get survey subjects on the sunny parts of the sidewalks, 5) We strongly recommend change of guidelines for urban street trees from "one row of street trees on 6m~8m intervals" to "street trees to make continuous shades".

The Developmental Pattern of Succeeding Regeneration after the Application of Shelterwood System in a Thrift-Mature Pinus koraiensis Plantation (잣나무 장령식재림에서 산벌작업 적용 후의 후계림 발달 양상)

  • Kim, Ji Hong;Kang, Sung Kee
    • Journal of Korean Society of Forest Science
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    • v.97 no.6
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    • pp.597-604
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    • 2008
  • Recognizing the necessity of the development of ecologically sound silvicultural system for the mature Korean pine (Pinus koraiensis), this study was carried out to examine the invasion and growth of understory vegetation after partial cutting. In 1997, the age class VII Korean pine forest in the Experimental Forest of Kangwon National University was opened up about 50% by modified shelterwood cutting with site preparation to induce succeeding regenerations. After 10 years, plenty of hardwood have come to the stand, forming understory vegetation. The abundance and composition of understory vegetation was periodically investigated in the ten $10m{\times}10m$ permanent sample plots, estimating importance values, species diversity index and the distribution of diameter and height of the understory vegetation. Encouraged by canopy opening, the coverage of understory reached perfect closure, composed of 22 tree species and 20 shrub species in 2007. Morus bombycis occupied 29.6% of the total importance value and Cornus controversa was 17.0%, followed by Styrax obassia, Quercus aliena, Quercus mongolica, Acer mono, and Pinus koraiensis. In the year of 2000 the species diversity was highest as 2.547 with 26 tree species and deceasing thereafter, showing 2.220 with 22 tree species in 2007. As understory layer was thickly covered and got grow bigger, some shade intolerant species were disappeared, lowering species diversity. In 2007 the biggest tree was a Quercus aliena with 11.3 cm of DBH and the tallest tree was a Cornus controversa with 9.8m of height. The frequency distribution of number of trees by diameter and height classes formed the inverted-J-shaped curve, supposed to be typical uneven-aged stand.

Natural Regeneration Characteristics of Pinus koraiensis-Broadleaved Forests after Selective Cutting in Mt. Changbai (장백산지역(長白山地域) 잣나무-활엽수(闊葉樹) 천연림(天然林) 택벌(擇伐) 적지내(跡地內) 천연갱신(天然更新) 특성(特性))

  • Kim, Yong-Huan;Lee, Don Koo;Kang, Ho-Sang
    • Journal of Korean Society of Forest Science
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    • v.94 no.1 s.158
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    • pp.6-10
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    • 2005
  • This study was conducted to understand the dynamics of naturally regenerated seedlings and saplings in 28years after selective cutting at natural Korean pine-broadleaved forests in Mt. Changbai. The number of naturally regenerated tree species was 16 species in 28 years after selective cutting. The appearance rate of naturally regenerated tree species was 56 percentage and the early-successional tree species of Acer ukurunduense, Acer mono, Acer pseudosieboldianum, Prunus padus var. pubescens, and Maackia amurensis were found in the first 10 years after selective cutting. The seedlings and saplings of shade-tolerant tree species of Pinus koraiensis, Acer mandshuricum, Ulmus laciniata were appeared and the appearance rate was higher than 75% after 15 years while it showed little changes from 19 years after selective cutting. The distribution density of seedlings and saplings of regenerated tree species in selective cutting area was 5,500~6,100 trees per hectare in the first 10 years, and it increased gradually along with the restoration of disturbed area and it could reach 7,500 trees per hectare after 15 years.

The Status and Prospect of Poplar Research in Korea (포플러 연구현황과 전망)

  • 구영본;여진기
    • Journal of Korea Foresty Energy
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    • v.22 no.2
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    • pp.1-17
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    • 2003
  • Populus species have been as a model species in tree breeding and we have enormous varieties resulting from the poplar breeding because of their fast growth performance and short rotation age. New varieties developed in Korea are common italian poplar(P euramericana, I-214, I-476), P euramericana“Eco 28”(Italian poplar No.1) and p. deltoides“Lux”(Italian poplar No.2), which were introduced from foreign countries. As hybrid polars, Hyun-Sasi(p. alba ${\times}$ P. glandulosa No.1, No.2, No.3, No4.), P. nigra x P. maximowiczii and P. koreana x P. nigra val. italica, were developed, and P. davidiana was selected as the result of selection breeding The total plantation areas covered with the new varieties are 935,162ha that include 745,773ha of P. euramericana, 184,636ha of P. alba x P. glandulosa, and other new varieties are 4,735ha. The new poplars are contributed to increase farmer's income as well as bare land tree-planting in Korea. The technologies associated with the poplar species were developed, such as the determination of optimum site for new the poplar species, the crossing method between incompatible poplar species, and the vegetative mass propagation. In the future, poplar species will be considered for phytoremediation species at contaminated areas such as landfill sites or with lives stock's waste water as well as wood production, a shade tree like road-side tree and public park tree.

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Mid-term (2009-2019) demographic dynamics of young beech forest in Albongbunji Basin, Ulleungdo, South Korea

  • Cho, Yong-Chan;Sim, Hyung Seok;Jung, Songhie;Kim, Han-Gyeoul;Kim, Jun-Soo;Bae, Kwan-Ho
    • Journal of Ecology and Environment
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    • v.44 no.4
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    • pp.241-255
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    • 2020
  • Background: The stem exclusion stage is a stage of forest development that is important for understanding the subsequent understory reinitiation stage and maturation stage during which horizontal heterogeneity is formed. Over the past 11 years (2009-2019), we observed a deciduous broad-leaved forest in the Albongbunji Basin in Ulleungdo, South Korea in its stem exclusion stage, where Fagus engleriana (Engler's beech) is the dominant species, thereby analyzing the changes in the structure (density and size distributions), function (biomass and species richness), and demographics. Results: The mean stem density data presented a bell-shaped curve with initially increasing, peaking, and subsequently decreasing trends in stem density over time, and the mean biomass data showed a sigmoidal pattern indicating that the rate of biomass accumulation slowed over time. Changes in the density and biomass of Fagus engleriana showed a similar trend to the changes in density and biomass at the community level, which is indicative of the strong influence of this species on the changing patterns of forest structure and function. Around 2015, a shift between recruitment and mortality rates was observed. Deterministic processes were the predominant cause of tree mortality in our study; however, soil deposition that began in 2017 in some of the quadrats resulted in an increase in the contribution of stochastic processes (15% in 2019) to tree mortality. The development of horizontal heterogeneity was observed in forest gaps. Conclusions: Our observations showed a dramatic shift between the recruitment and mortality rates in the stem exclusion stage, and that disturbance increases the uncertainty in forest development increases. The minor changes in species composition are likely linked to regional species pool and the limited role of the life-history strategy of species such as shade tolerance and habitat affinity. Our midterm records of ecological succession exhibited detailed demographic dynamics and contributed to the improvement of an ecological perspective in the stem exclusion stage.

A Study on Optimum Tree Planting Density for Apartment Complex (아파트단지 조경수 적정식재밀도 연구)

  • Oh, Choong-Hyeon;Jeong, Wook-Ju;Lee, Im-Kyu;Kim, Min-Kyung;Park, Eun-Ha
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.6
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    • pp.140-147
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    • 2012
  • This study was conducted to investigate optimum planting density for apartment complex. The validity of Landscape Architecture Criteria of Korea was checked for it. We compared our field data with Landscape Architecture Criteria. In this step, the tree density of urban forest was regarded as standard. Field study was examined in 3 apartment complexes located in capital area, especially completed during these 10 years. 10 sites in each complex were selected and tree density per unit area were calculated. This field study data was divided standard size and large size which received weight. And, it was compared and analyzed. And crown projected area(CPA) was calculated considering proper growth of low vegetation and sufficient shade. The outcome shows that minimum size of Landscape Architecture Criteria is rational. But, in the case of planting large size tree received weight, tree density was short comparing with the tree density of urban forest and CPA was less than 50%. By the result of field study in 3 apartment complex, the tree density of apartment complex satisfied or exceeded Landscape Architecture Criteria. But, in the case of planting large size tree, tree density and CPA show high density due to addition planting for deficient landscape. Therefore, the revision of the Landscape Architecture Criteria was required such as deletion or minimization of the weighted clause about the large size tree and regulate the limit CPA not less than 50% and not more than 100%.

An Actual Measurement on Safety of Play Equipments in the Outdoor Playground (어린이 놀이터 놀이시설의 안전도에 관한 조사)

  • 석주영;안옥희;박인전
    • Journal of the Korean housing association
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    • v.13 no.2
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    • pp.47-53
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    • 2002
  • The purposes of this study actually measure to the dimension and the quality of material play equipment's examine whether they meet safety standards or not, and intend to offer basic data to present proper safety standards concerning the dimension of play equipment in the end. The subjects for this study were 59 outdoor playgrounds, 30 among them located in apartment sites and the remainder did in residential districts. The time of actual measurement was in June 1999, and June 2000. Data were analyzed into frequency, percentage, mean, and standard deviation by using SPSSWIN program. The main results were as follows.: First, more than half of playgrounds were assessed for being traffic hazards due to the adjacent streets. And they were hardly equipped with the toilet and drinking water facilities, but were almost equipped with the shade of a tree and benches. Second, it was caused in inconvenience of children's use and difficulty of play equipments'management, since the quality of play equipments materials was consisted of wood or metal. Third, the standards for swing and slide were established in detail and actual measurement's results were suitable to standards'value as well, whereas the standards for seesaw and climber were not in detail and they did not design or install suitably.

New Records of Powdery Mildews from Ornamental Trees in Korea (I) (관상수목의 미기록 흰가루병(I))

  • Shin, Hyeon-Dong;Yang, Sung-Il;Lee, Sang-Hyun
    • The Korean Journal of Mycology
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    • v.27 no.2 s.89
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    • pp.158-163
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    • 1999
  • Powdery mildew diseases previously unrecorded in Korea were noticed on four species of ornamental trees. Field observations on each disease were described and the causal fungi were identified. Powdery mildew of Symplocos chinensis for. pilosa was found to occur mildly, especially on plants growing in shade. The causal fungus was identified as Microsphaera nomurae U. Braun. Cornus florida was found to be infected with Microsphaera pulchra Cooke & Peck and supposed to be epidemic in nursery. Powdery mildew of Malus baccata occurred on young leaves and herbaceous stems in nursery. The causal fungus was classified as Podosphaera leucotricha (Ellis & Everh.) Salmon. Powdery mildew of Ulmus macrocarpa was found to occur in autumn and severe on young shoots. Uncinula kenjiana Homma was identified as the causal fungus.

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A Study on the traditional Garden Style of Sang Ju Districts in Korea (상주지방의 고주택 정원양식에 관한 연구)

  • 박영달;신영철
    • Journal of the Korean Institute of Landscape Architecture
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    • v.20 no.2
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    • pp.62-75
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    • 1992
  • To investigate the traditiional gaden style of Sang ju Districts, 5 renown houses of noble family in Lee Dynasty were chosen to surey the environmental landscape and characteristics inner and outer space. 1. Traditional houses were located in natural environments based on topography(pung su-ji ri : forming philosophy of Taoism Buddbism and Korean native Sharmanism) which were reflected the 5 Elements of positive and Negative(Yin and Yang 5 Elements) 2. The formation of space is made of oblong by fence arrangement of dwelling housos has An Chae and Sa Rang Chae, and inner court of Anchae has style of oblong, and outer court of Sa Rang Chae has style of sililar oblong. Inner court is closed and outer is half opened. 3. Flow planning is straight and blique line because arrangement of dwelling houses is formed by theory of Dong-Suh Sa Taek(東西四宅), the flowing is complicated and connected from gate to room of An Chae. 4. Character of garden have simple neat whereas vegetable yard, green shade tree, and fruit trees have. Houses were built with their natural environments and streams in order to borrow landscaping in Sa Rang Chae. Specially they were not built pond. 5. Houses has one or two vegetable yard along inner and outer space and are seen as mixed planting more deciduous trees than evergreen trees.

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