• The Korean Journal of Ecology
• /
• 제27권3호
• /
• pp.161-164
• /
• 2004

본 실험에서는 Thuja 속 7종(Thuja orientalts, T. orientalis 'Avrea Nana', T. orientalis cv. compacts, T. occidentalis, T. occidentalis 'Boothii', T. occidentalis 'Pumila', T. occidentalis 'Tiny Tim')의 침엽에 함유된 monoterpenenoids를 GC-MS로 분석하여 종간을 비교하였다. 분석결과 총 30종류의 성분이 검출되었는데 그 중 α-pinene, camphene, sabinene, myrcene, limonene, bonyl aetate, γ-terpinene, α-terpinenyl acetate는 7종 식물모두에서 검출되었다. Thuja속 7종에서 추출된 monoterpenenoids는 종간에 차이가 나타났으며 Thuja orientalis 'Avrea Nana'(11 Compounds)는 가장 작은 성분이 나타났고 Thuja occidentalis 'Pumila'(26 Compounds)는 가장 많은 종류의 성분이 검출되었다. 검출된 성분을 토대로 종간의 유사성을 PAUP(Phylogenetic Analysis Using Parsimony) 프로그램으로 분계분석을 하였다. 분계도는 4가지 형태가 나타났고 Thuja occidentalis와 Thuja occidentalis 'Boothii'가 가장 유사한 유연관계를 보였다.

• 한국조경학회지
• /
• 제18권2호
• /
• pp.57-65
• /
• 1990

To select suitable siecies for barrier trees in the middle tmperature forest zone of Korea, sprout ratio, verdi cal density ratio and impenetrability were analyzed for 41 species including 9 evergreen conifer trees which had been transplanted 18 years ago and maintained as a hedge at Pocheon - Gun, Kyonggi -Do, Korea. 1. The species with high sprout ratio of hedges were Rosa multiflora, Lonicera maackii, Chamaecyparis pisifera, Thuja occidentalis in order at the upper portion, Thuja occidentalis, Rosa multiflora, Chamaecyparis pisifera, in order oa the middle portion, and Thuja occidentals, Chamaecyparis pisigera, Rosa multiflora, Cercdiphyllum japonicum, Cornus kousa, Ulmus pumila, Robinia pseudoacacia in order at the lower portion of hedges. 2. the species with high vertical density ratio were Thuja occidentalis, Chamaecyparis pisifera, Weigela subsessilis, Acer ginnala in order. 3.The species with hight impnetrability were Thuja occidentalis, Chamaecyparis pisifera, Forsythia Koreana, Juniperus rigida, Juniperus chinensis, Pinus strobus in order. 4. the values of correlation coefficents between the sprout ratio and impenetrability are given in table 3 and positive significant correlations can be observed in conifer trees.5. The species with high suitability for tree barrier were Thuja occidontalis, Chamaecyparis pisifera, Acer ginnala, Juniperus chinensis, Rosa multiflora, Counus kousa, Cercidiphyllum japonocum, Weigela subsessilis, Cornus officinalis, Philadelphus schrenckii in order.

• The Korean Journal of Ecology
• /
• 제18권3호
• /
• pp.385-395
• /
• 1995

Species effects on soil nitrogen mineralization and nitrification in the top 15 cm of soil were evaluated using the buried-bag incubation method in three coniferous plantations in the Kwangneung Experimental Forest, Kyonggi Province. The plantations were established on a similar soil in 1927, and included Larix decidua, Pinus strobus, and Thuja occidentalis. Ten soil samples within each plantation were taken during an entire growing season (May 2~Oct. 30, 1994). Mean daily nitrogen mineralization rates during 45-day in situ soil incubations were significantly different among species and incubation dates. Growing season nitrogen mineralization also differed significantly among species and ranged from 47.7 mg N/kg soil for Larix decidua to 21.5 ma N/kg soil for Thuja occidentalis. Growing season nitrification differed significantly among species and comprised from 93% to 100% of the total growing season nitrogen mineralized. We speculated that organic matter contents and quality might control nitrogen mineralization and nitrification in these soils.

• Journal of the Korean Wood Science and Technology
• /
• 제34권6호
• /
• pp.21-28
• /
• 2006

본 연구는 목탄의 모양과 탄화된 수종의 종류에 따른 토양개량 효과를 시험하기 위해 수행되었다. 결과에 따르면 서양측백과 칠엽수 묘목 모두 무처리 토양에서보다 목탄 처리 토양에서 더 잘 자랐다. 분말탄의 경우, 서양측백나무 묘목 생장은 잣나무 목탄으로 처리된 토양에서 가장 좋았으며 낙엽송, 파티클보드, 상수리나무 목탄 순으로 컸다. 입상탄의 경우 묘목 생장은 낙엽송, 파티클보드, 잣나무 목탄의 순으로 컸다. 또한 토양공극과 유기물 함량도 무처리 토양에서보다 목탄 처리 토양에서 더 큰 것으로 분석되었다. 목탄 처리 토양에서 묘목생장이 더 좋았던 것은 근계에서의 통기성과 유기물 흡착이 증가되었기 때문인 것으로 추정된다.

• 한국농공학회논문집
• /
• 제63권6호
• /
• pp.39-47
• /
• 2021

Reduction effect of the spread of odorant and fine dust through windbreak trees can be predicted through numerical analysis. However, there is a disadvantage that a large space and destructive experiments must be carried out each time to calculate the aerodynamic coefficient of the tree. In order to overcome these shortcomings, In this study, we aimed to estimate the aerodynamic coefficient (C₀, C₁, C₂) by using image processing. Thuja occidentalis, which can be used as windbreak were used as the material. The leaf area index was estimated from the leaf area ratio using image processing with leaf weight, and the optical porosity was calculated through image processing of photos taken from the side while removing the leaves step-by-step. Correlation analysis was conducted with the aerodynamic coefficient of Thuja occidentalis calculated from the wind tunnel test and leaf area index and optical porosity calculated from the image analysis. The aerodynamic coefficient showed positive and negative correlations with the leaf area index and optical porosity, respectively. The results showed that the possibility of estimating the aerodynamic coefficient using image processing.

• 한국대기환경학회지
• /
• 제7권3호
• /
• pp.208-218
• /
• 1991

To compare the resistance of landscape trees by acid rain, simulated acid rain was treated on the seeds of 6 coniferous species (Pinus densiflora, Pinus thunbergii, Pinus koraiensis, Taxus cuspidata, Cedrus deodara, Thuja occidentalis) and 6 broad-leafed species (Ligustrum obtusifolium, Acer Buergerianum, Acer Ginnala, Styrax obassia, Cornus Kousa, Magnolia obovata). The experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agri-Tech Junior College. The seeds of 12 tree species were planted on the nursery soil in the early spring of 1991. The regime of artificial acid rain, in terms of spray frequency per monthly and spray amount at year records. Simulated acid rain (pH 2.0, pH 4.0, pH 5.6 as control) containing sulfuric and nitric acid in the ratio of 3:2 (chemical equivalant basis) diluted ground water, were treated on the experimental plants under condition of cutting off the natural precipitation with vinyl tunnel, during the growing season (April 8 to August 31) in 1991. Seedling establishment, seedling growth and nutrient contents in needles and leaves were measured and compared among the treatment. The results were summerized as follows; 1. In general, coniferous species were more resistant than broad-leafed species in the resistant comparisons of landscape trees by simulated acid rain. But there were resistant tree species to acid rain among the broad-leafed species. 2. Among 6 coniferous species used in this experiment, Pinus densiflora, Pinus koraiensis, Taxus cuspidata, Cedrus deodara and Pinus thunbergii revealed the resistant tree species to acid rain. But Thuja occidentalis was very susceptible to acid rain, because of no germination in pH 2.0 treatment plot of acid rain. 3. Among 6 broad-leafed species used in this study, Magnolia obovata, Styrax obassia and Ligustrum obtusifolium showed relative resistant tree species to acid rain. But Acer Buergerianum, Acer Ginnala and Cornus Kousa were very susceptible to acid rain, because of no germination in pH 2.0 plot of acid rain treatment.

• 한국농공학회논문집
• /
• 제63권5호
• /
• pp.63-71
• /
• 2021

Windbreak forests, which have a windproof effect against strong winds, are known to be effective in reducing the spread of odors and dust emitted from livestock farms. The effect of reducing the spread of odors and dust can be estimated through numerical models such as computational fluid dynamics, which require aerodynamic coefficients of the windbreaks for accurate prediction of their performance. In this study, we aimed to evaluate the aerodynamic coefficients, Co, C₁, C₂, and α, of two windbreaks, Thuja occidentalis and a mesh net, through wind tunnel experiments. The aerodynamic coefficients were derived by the relation between the incoming wind speed and the pressure loss due to the windbreaks which was measured by differential pressure sensors. In order to estimate the change in the aerodynamic coefficient concerning various leaf density, the experiments were conducted repeatedly by removing the leaves gradually in various stages. The results showed that the power law regression model more suitable for coefficient evaluation compared to the Darcy-Forchheimer model.

• 인간식물환경학회지
• /
• 제23권5호
• /
• pp.507-519
• /
• 2020

Background and objective: This study analyzed the growth characteristics, in relation to the soil moisture content, of trees planted in an environment with limited soil depth to provide the baseline data for effective irrigation management. Methods: The experimental treatment was divided into soil moisture contents (SMC) of 20%, 15%, 10%, 5%, and 1%, and the respective watering times were set accordingly. As for plant materials, Nandina domestica, Euonymus alatus, Thuja occidentalis, Hibiscus syriacus, Pinus densiflora, and Pyracantha angustifolia, were chosen for this study, because they are highly likely to be used in urban street environments. Results: The minimum irrigation point suitable for each species was determined by considering various aspects of visual quality and water efficiency in terms of plant growth, including characteristics such as height, root diameter, rootlet development, and weight. Our results indicate that N. domestica should be watered so that the moisture content of the soil is of at least 5%, based on the balance between the stem and roots, as well as on visual quality. E. alatus and P. angustifolia are suitable for watering that results in at least 10% SMC, considering the height, root growth, weight, and visual quality of plants. As for T. occidentalis, it showcases moderate growth with a soil moisture content of at least 5%. Finally, the minimum irrigation time required to obtain 15% SMC is appropriate, in terms of plant growth, fresh weight, and visual quality, for H. syriacus and P. densiflora. Conclusion: This study suggested a basic irrigation guideline for container gardens where trees planted in environments with limited soil depth can be managed so that they are visually appropriate and in good condition of growth.

• 인간식물환경학회지
• /
• 제23권3호
• /
• pp.333-345
• /
• 2020

Background and objective: The purpose of this study was to provide basic data on trees that can be used for planting design and construction for permanently shaded areas by grasping the growth status of trees according to the daylight conditions of the outdoor spaces of apartment complexes. Methods: On the recently completed apartment complexes, daylight conditions were analyzed by using daylight simulations utilizing Solar Access Analysis of Ecotect Analysis. With a criteria for assessment of tree condition, the defect rate of trees planted in permanently shaded areas and green spaces with good daylight conditions was analyzed to suggest trees applicable to permanently shaded areas. The first tree survey was conducted from November 18, 2019 to February 15, 2020, focusing on trees planted in permanently shaded areas, and the second tree survey of all the trees planted on the study sites including permanently shaded areas was conducted from March 16 to March 30, 2020. Results: Evergreen trees which are classified as shade intolerant trees including Pinus densiflora, Thuja occidentalis, and Abies holophylla showed a higher defect rate of trees among the trees planted in permanently shaded areas. Taxus cuspidata, Zelkova serrata, Cornus kousa, Chionanthus retusus and Acer palmatum which are classified as shade tolerant trees and shade moderate tolerance trees seemed to be able to be used in the plant design of permanently shaded areas in apartment complexes because the trees showed good growth and a low tree defect rate. In addition, although it was excluded from the analysis due to a small number of samples, Sorbus commixta and Prunus cerasifera var. atropurpurea also can be used for planting in permanently shaded areas. Conclusion: The daylight simulation technique used to analyze permanent shaded areas in this study can be used as an analysis tool considering the daylight environment at the stages of design and construction, and additional research will be required to analyze tree growth according to daylight conditions through data accumulation and monitoring by managing records throughout the entire life cycle of trees in the process of planting and maintenance.

• 현장농수산연구지
• /
• 제10권1호
• /
• pp.101-111
• /
• 2008

As the quality of life improves, people want to live in more pleasant environment with beautiful trees, clean air and water. They are keenly interested in environmental issues as well as living environment of apartment which is a trademark of modern life. With this situation, the function and roles of landscaping trees have been recognized as a critical factor to improve living environment. As people have asked for more demands on those trees, it has raised more issues on the defect of trees and is required the solution to those issues. So, the purpose of this study was to survey the reasons of defects and find out those solutions. The data on defects in 1990s was referenced to the reports issued by SH Corporation in 1994 and 1997. The data on defects in 2000s are collected from March, 2006 to May 2006 based on the survey for apartments already constructed by Korea Housing Corporation. The results of the survey were shown that, in the year of 1994, landscaping trees causing high rate of defects were Acer buergerianum (92%), Pinus densiflora(85.7%), Celtis sinensis(80%), Cydonia sinensis(75%) and Diospyros kaki(66.6%), and in the year of 1997, landscaping trees causing high rate of defect were Ziziphus jujuba(100%), Cornus alba(65.2%), Diospyros kaki(60%), Thuja occidentalis(60%), and Metasequoia glyptostroboides(42%). And, in the year of 2006, landscaping trees causing high rate of defect were Sophora japonica(100%), Taxus cuspidata(80%), Magnoila quinquepeta (75%), Acer palmatum(62.5%) and Ginkgo biloba(50%). Because the reasons of defects were various according to the conditions including the climate, location, time and landscaping trees carried into the work area, we present the problems and solutions to those defects. Since the landscaping trees are living creatures, the factors of defects were various and complicated according to the site condition. So, in the period of warranty, contractor should designate the tree manger who can recognize the situation and take suitable action within timely manner.