• Korean journal of applied entomology
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• v.61 no.3
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• pp.481-496
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• 2022

In order to establish an effective pest control strategy, we investigated the occurrence of lepidopteran insects in the major trees growing in urban forests from 2019 to 2021. In total, we recorded 76 species of 14 families in Prunus spp., 40 species of eight families in Acer spp., 43 species of 10 families in Zelkova serrata, 28 species of seven families in Rhododendron spp., and 10 species of four families in Hibiscus syriacus. Among these, Hyphantria cunea and Lymantria dispar were recorded from all five tree taxa monitored. The most frequently occurring species in the different tree groups were as follows: H. cunea and Phalera flavescens in Prunus yedoensis, Epinotia ulmicola in Z. serrata, and Rehimena surusalis in H. syriacus. H. cunea also occurred in Rhododendron spp. and Acer spp., although the numbers were lower than those recorded in Prunus spp. and Z. serrata. Our results highlight the importance of focusing on the frequency of occurrence of lepidopteran insects in Prunus spp. and Z. serrata, whereas the presence of these insects in both Acer spp. and Rhododendron spp. Appears to be less problematic. From the perspective of reducing the risks to human health, our findings indicate that the application of pheromones for monitoring lepidopteran species and the use of mating disruptors would be desirable approaches that would contribute to minimizing the spraying of pesticides in urban forests.

• Mycobiology
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• v.32 no.3
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• pp.105-109
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• 2004

Erysiphe azaleae, a powdery mildew fungus on Rhododendron spp., was originally described from North America, and has only recently been recorded in Germany, England, Switzerland and Poland. The present paper records plentiful collections of this species from Poland, and provides additional information of its anamorphic state for taxonomic purposes.

• The Korean Journal of Ecology
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• v.28 no.4
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• pp.207-214
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• 2005

The present study was undertaken to classify and describe the Quercus spp. forests in the lower montane zone of Mts. Bakdal, Gyemyeong, Boryeon, Worak, Cheondeung, Joryeong, Gungmang, Buyong and Sirubong in Chungbuk Province, Korea using the methodology of the Z.-M. school's phytosociology. The Ouercus spp. forests were classified into three communities and two groups; A. Quercus variabilis community A-1. Quercus serrata-Quercus acutissima group, A-2. Quercus mongolica group; B. Quercus mongolica-Rhododendron schlippenbachii community; C. Quercus dentate-Chloranthus japonicus community. These vegetation units were arranged by human interference and a gradient of environmental complex such as altitudes, and also were corresponded relatively well with a result of cluster analysis (UPGMA) based on the dominance of component species.

• Korean Journal of Environment and Ecology
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• v.28 no.6
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• pp.725-740
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• 2014

To figure out the vegetation situation in the ridge of the Naknam-Jeongmaek, six intensive survey sites were selected considering environmental factors and human interferences, 132 quadrats (area $100m^2$) were installed to survey appearing species of trees and major environmental factors, and the characteristics of vegetation structures were analyzed. The surveyed plots were divided into six groups according to the analysis of classification by TWINSPAN; Quercus mongolica-Q. variabilis community, Pinus densiflora-Q. dentata community, Chamaecyparis obtusa community, Q. mongolica-P. densiflora community, P. densiflora-P. thunbergii community, P. koraiensis community, Rhododendron spp.-Lespedeza cyrtobotrya community. P. densiflora-Q. dentata community, Q. mongolica-P. densiflora community, and P. densiflora-P. thunbergii community are expected to be succeeded by deciduous oaks because the power of deciduous oaks is strong in their lower layer. C. obtusa community, P. densiflora community, and Rhododendron spp.-L.cyrtobotrya community are artificial forests that were artificially formed and are expected to be maintained in the current state for some time because the dominance value of planted species of trees is high. Most vegetations in Naknam-Jeongmaek were secondary forests or artificial forests formed for forest tree production and forestation for erosion control. In particular the top regions and hilly sections of the mountain were mostly dominated by deciduous oaks such as Q. mongolica, Q. variabilis showed some P. densiflora community competing with deciduous oaks. On the other hand, low sections and regions adjacent to the city showed severe artificial interference since exotic species such as P. thunbergiil, C. obtusa, P. koraiensis, and Rhododendron spp. were planted.

• Korean Journal of Plant Resources
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• v.23 no.4
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• pp.374-378
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• 2010

Determining plant moisture characteristics is an essential study not only for cultivation, but also for ex-situ conservation. In this study, employing pressure-volume curve we examined moisture characteristics of Rhododendron micranthum, known as rare plant, with the aim of its ex-situ conservation. Several individuals growing in Mt. Worak, Youngwol-gun Yeonha-ri and Bongwa-gun Seokpo-ri were selected for this study, from which we collected leaves. The original bulk osmotic pressure at maximum turgor(${{\Psi}_o}^{sat}$)was -1.5 MPa in those of Mt. Worak and Seokpo-ri, which is somewhat lower than that of Yeonha-ri(-1.2 MPa). It appeared that the osmotic pressure at incipient plasmolysis(${{\Psi}_o}^{tlp}$) of leaves collected in both Mt. Worak and Seokpo-ri were -1.29 MPa, and -1.26 MPa, respectively, which are lower than that of Yeonha-ri(-1.02MPa). Maximum bulk modulus of elasticity($E_{max}$) was 14.0 MPa, 8.67 MPa in leaves collected from both Seokpo-ri and Mt. Worak, respectively, those value of which were approximately 3 times higher than that of Yeonha-ri(4.00 MPa). The values of $RWC_{tlp}$(Relative water content at incipient plasmolysis) of leaves collected in three areas, were roughly 83%, suggesting that Rhododendron micranthum has relatively high capability of containing water. Our finding on moisture characteristics of Rhododendron micranthum is similar to those of other Rhododendron spp. We suggest that individuals growing in both Worak and Seokpo-ri, are preferable to those in Yeonha-ri for ex-situ transplantation since those individuals are found to have better drought resistance.

• The Korean Journal of Mycology
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• v.46 no.1
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• pp.69-74
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• 2018

The Rhododendron powdery mildew fungus Erysiphe izuensis has been recorded throughout Asia, including China, Japan, Korea, and Russia. In Korea, E. izuensis has been identified based on morphological characteristics of the anamorph found on introduced Rhododendron spp. We here describe the first identification of E. izuensis collected from Rhododendron yedoense f. poukhanense in Korea. Morphological characteristics of the teleomorph as well as internal transcribed spacer sequences of the species are provided. Moreover, we describe the characteristics of the primary conidia and conidial surface pattern of E. izuensis for the first time.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.213-217
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• 2000

In order to select more proper plants for phytoextraction at the heavy metal polluted areas, 11 species of non-edible plants were cultivated at the cadmium(Cd) and Lead(Pb) treated soils and analyzed the content of the absorbed Cd and Pb in each part of plants. Plants include three fibers(Linum usitatissimum, Cannabis sativa, Gossypium spp.), three flowers(Calendula officinalis, Rhododendron lateritium, Portulaca grandiflora), and five trees(Pinus thunbergii, Magnolia kobus, $Populus\;nigra\;{\times}\;P.$ maximowiczii, Euonymus japonica, Fraxinus rhynchophylla). Yield of tree species were higher than that of fiber and flower species. Cd and Pb were highly accumulated in root rather than leaves and stems. The Cd content of plants was in the order Portulaca grandiflora > Calendula officinalis > Gossypium spp. > Linum usitatissimum, Pb was Cannabis sativa > Linum usitatissimum > Fraxinus rhynchophylla. Total absorbed Cd by each plant was in the order $Populus\;nigra\;{\times}\;P.$ maximowiczii > Euonymus japonica > Rhododendron lateritium, but Pb was $Populus\;nigra\;{\times}\;P.$ maximowiczii > Rhododendron lateritium > Euonymus japonica. Total absorbed Cd and Pb contents in plants were negatively correlated with the residual Cd and Pb in the treated soils. It was estimated that $Populus\;nigra\;{\times}\;P.$ maximowiczii, Euonymus japonica, Fraxinus rhynchophylla, and Rhododendron lateritium were the most effective species for phytoextraction in the polluted area considering yield and heavy metal uptake.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.6
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• pp.41-55
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• 2011

This study was carried out to survey and analyze the transition of landscape plants on an apartment complexes in the 1990's and 2000's. The results are summarized as follows; The ratio of landscape area was increased from 30.0% to 34.7%. The number of trees per 100 square meter decreased from 22.5 to 15.7. The number of shrub per 10 square meter increased from 19.3 to 38.7. Species of Evergreen tree were increased 21 to 39. The species that a lot of use continuously were Pinus densiflora, Pinus strobus and Taxus cuspidata. The species that increase use were Abies holophylla and Pinus densiflora for. multicaulis. The species that decrease use exceedingly, were Pinus parviflora, Juniperus chinensis, Pinus koraiensis and Thuja orientalis. The species that do not use were Cedrus deodara. Species of deciduous tree were increased 42 to 68. The species that a lot of use continuously were Zelkova serrata, Acer palmatum, Diospyros kaki, Prunus armeniaca and Prunus yedoensis. The species that increase use were Lagerstroemia indica, Chionanthus retusa, Cornus officinalis, Styrax japonica, Sorbus alnifolia, Prunus mume, Cercidiphyllum japonicum, Acer triflorum, Prunus sargentii, Chaenomeles sinensis and Cornus kousa. The species that decrease use exceedingly, were Acer buergerianum, Sophora japonica, Malus spp., Ginkgo biloba, Zizyphus jujuba var. inermis, Platanus orientalis and Albizzia julibrissin. The species that do not use were Liriodendron tulipifera, Acer saccharinum, Ailanthus altissima and Paulownia coreana. Species of shrub were incresed 39 to 65. The species that a lot of use continuously were Buxus koreana, Rhododendron schlippenbachii for. albiflorum, Rhododendron schlippenbachii, Syringa dilatata and Euonymus japonica. The species that increase use were Rhododendron indicum, Ilex serrata, Spiraea prunifolia var. simpliciflora, Taxus cuspidata var. nana, Kerria japonica, Rhododendron yedoense var. poukhanense, Euonymus alatus, Sorbaria sorbifolia var. stellipila, Nandina domestica, Cornus alba, Hydrangea serrata for. acuminata, Prunus tomentosa, Deutzia parviflora and Pyracantha angustifolia. The species that decrease use exceedingly, were Hibiscus syriacus, Rosa multiflora var. platyphylla, Chaenomeles lagenaria and Rosa spp. The species that do not use were Juniperus chinensis var. sargentii, Jasminum nudiflorum and Sasa borealis.

• The Korean Journal of Ecology
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• v.15 no.3
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• pp.231-246
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• 1992

In order to estimate effects of air pollution for pinus thunbergii forests arounding onsan industrial complex, structure of forest vegrtation was surveyed. In the survey of forest vegetation, pinus densiflora have been died or being withered, and importance value(I.V) of rhododendron mucromulatum and lespedeza spp. were low at the vicinity of industrial complex. Especially lespedeza maximowiczii and l. maritima were not entirely appeared at the vicinity of industrial complex. I.V. of quercus serrata, robinia pseudoacacia and alnus firma were preferably high at the vicinity of industrial complex, and those of smilax china, rubus crataegifolius and rhus trichocarpa were similar at every site and it could be guessed that those had a tolerance. Number of species had a difference over 10 species at the vicinity of industrial complex as compared with those of remote sites, and species diversity showed highly at the farther sites of industrial complex, and also at the low layer, number of species, species diversity and evennes were low at the vicinity of industrialcomplex and species weakened to air pollution were disappearing. It was possible that forest vegetation would be changed from pinus spp. to community of a. firma and r. pseudoacacia.

• The Journal of Natural Sciences
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• v.10 no.1
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• pp.63-71
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• 1998

This research was conducted to control flowering of azalea (Rhododendron spp.) by shading, chilling and gibberellin treatments. Higher shading among treatments resulted in extended duration of flowering (DF) and increased number of flowers (NF) in all varieties tested. Number of days to flower (NDF) was increased in 'Ripple' by shading treatment, but this was not affected in other was vice verse in 'Reinhold Ambrosia' resulting in decreased NDF. Chilling treatment followed by high shading increased NDF and shortened DF in 'Inga' and 'Ripple', but that extended NDF and DF and increased NF in 'Reinhold Ambrosia'. In flowering response to $GA_3$ resulted in decreased NDF and increased NF. These results indicated that treatments of shading, chilling and gibberellin to azalea extended DF and increased NF, but NDF appeared different according to varieties.