• Korean Journal of Plant Resources
• /
• v.34 no.2
• /
• pp.172-176
• /
• 2021

The Hosta 'Hwangnarae' was bred at the Korea National Arboretum, which was induced using ethyl-methanesulfonate (EMS) to obtain mutants. Among the leaf variegated Hosta plants, some with yellowish-green color pattern on the edge of the leaves was selected. They were cultivated through vegetative production. Assessment of the botanical characteristics was executed for six years from 2013 to 2018. Major characteristics such as yellowish-green color pattern on the edge of leaves appeared uniformly and was finally selected in 2019. The Hosta 'Hwangnarae' that have been bred in this way can prove to be useful as material for a ground cover plant or pot plant.

• Asian Journal of Turfgrass Science
• /
• v.24 no.1
• /
• pp.50-55
• /
• 2010

Five turfgrass species and 46 cultivars were investigated for difference of spring greenup and living ground cover. Turf color and Normalized Difference Vegetation Index (NDVI) for greenup were investigated between species and cultivars. Turf color and NDVI were showed significantly different among species and cultivars. Turf color was showed significantly different among 20 cultivars of kentucky bluegrass (Poa pratensis L.). NDVI was significantly difference among 20 cultivars of kentucky bluegrass and 6 cultivars of tall fescue (Festuca arundinacea Schreb). The percentage living ground cover was showed significantly different among creeping bentgrass (Agrostis palustris Huds) cultivars and fineleaf fescue cultivars in spring.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.14 no.3
• /
• pp.201-209
• /
• 2016

The object of this study was to evaluate the separation distance from a temporary storage facility satisfying the dose criteria. The calculation of ambient dose rates took into account cover soil thickness, facility size, and facility type by using MCNPX code. Shielding effects of cover soil were 68.9%, 96.9% and 99.7% at 10 cm, 30 cm and 50 cm respectively. The on-ground type of storage facility had the highest ambient dose rate, followed by the semi-ground type and the underground type. The ambient dose rate did not vary with facility size (except $5{\times}5{\times}2m\;size$) due to the self-shielding of decontamination waste in temporary storage. The separation distances without cover soil for a $50{\times}50{\times}2m\;size$ facility were evaluated as 14 m (minimum radioactivity concentration), 33 m (most probably radioactivity concentration), and 57 m (maximum radioactivity concentration) for on-ground storage type, 9 m, 24 m, and 45 m for semi-underground storage type, and 6 m, 16 m, and 31 m for underground storage type.

• Korean Journal of Plant Resources
• /
• v.26 no.4
• /
• pp.516-518
• /
• 2013

A new leaf variegated cultvar 'White Edge' was developed by ethyle methane sulfonate(EMS) treatment on seed of Hosta minor. Among induced leaf variegated plant, some with white color on the edge of the leaves was selected. They were cultivated via vegetative propagation. 'White Edge' was finally selected through the test of characteristics from 2003 to 2005. Assessment of botanical characteristics was conducted for three years. The major characteristic of these cultivar is that they maintain uniformly all year round. 'White Edge'(Grant No.1880) was registered to the Korea Seed and Variety Service(KSVS) for commercialization in 2007. These cultivar are useful as materials for pot or as ground cover plants.

• Research in Plant Disease
• /
• v.10 no.4
• /
• pp.304-309
• /
• 2004

Girdling of trunk and rainproof installation over kiwifruit (Actinidia deliciosa) trees were turned out to alleviate bacterial blossom blight effectively in kiwifruit orchards. The disease was most effectively prevented by girdling of tree trunks with 20 mm width around April 10 before about 45 days of flowering stage of kiwifruit, but control efficiencies were not affected by height of girdling on trunks above the ground. Use of a transparent polyvinyl film to protect kiwifruit trees from rain was more effective than windbreak net to prevent the disease, irrespective of kinds of rainproof installation. Installation of partial rainproof vinyl cover over kiwifruit trees around March 10 before about 75 days of flowering stage of kiwifruit prevented most of the disease occurrence on kiwifruit. It is expected that girdling of tree trunks and installation of partial rainproof vinyl cover over kiwifruit trees will be practical as environmentally friendly control methods to manage bacterial blossom blight in kiwifruit orchards.

• Journal of Ecology and Environment
• /
• v.35 no.3
• /
• pp.235-242
• /
• 2012

Mikania micrantha, a neo-tropical vine, is spreading rapidly in the tropical part of Nepal and is now threatening the rural ecosystem including biodiversity and rural livelihoods. However, no attempt has been made to control the spread of M. micrantha. As a result, the vines are spreading freely and rapidly. After a thorough literature review and assessment of forest management practices, we proposed a manual cutting method, as it suits the Nepalese situation for several reasons: required labor is readily available, as local communities are managing forest patches, and the method does not have any potential adverse effects on non-target native species. Experimental plots were laid out in August 2011 to examine the effectiveness of manual cutting. Two different site types based on canopy coverage were selected and divided into three blocks based on cutting strategy. Four treatments were assigned across the experimental plots following a complete block design. We harvested above-ground biomass according to the assigned treatment. The results suggested that there should be at least two consecutive cuttings within a 3-week interval before flowering, and that three consecutive cuttings resulted in 91% mortality of the vines. In addition, cutting promoted regeneration of native plant species. Employing regular cutting operations can modify understory shade enhancing regeneration of native species, which is a desirable condition to constrain proliferation of M. micrantha. Periodic cuttings reduced the competitiveness of M. micrantha regardless of canopy openness, but native ground cover should be retained.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.25 no.4
• /
• pp.171-183
• /
• 1998

The purpose of this study was to analyze urban greenspace area and vegetation structure by land use types for both Chuncheon and Kangleung. Natural and agricultural lands were predominant in the study cites, as 75-80% of total area. Residential lands accounted for about 10%, and commercial and industrial lands(including transportation), 5-10%. Only 10-20% of urban residential and commercial area was covered with greenspace. Woody plant cover was 12-13%, and tree density was 1.5 trees/100$m^2$ for urban lands(all land use types except natural land) in both cities. The tree-age structure was largely characterized by young, growing tree population, and species diversity within a diameter class decreases as the diameter classes get larger. Urban lands of both cities had quite a similar species composition of woody plants (similarity index of 0.65). Street trees in Chuncheon were intensively pruned annually to protect the above ground utility lines. Some strategies were explored to solve problems found in the existing greenspace structures. They included increase of biomass and greenspace area through minimization of unnecessary impervious surfaces, creation of multilayered and multiaged vegetation structures, relocation of above ground utility lines and avoidance of intensive tree pruning, and establishment of greenspace proximity and connectivity.

• Journal of Forest and Environmental Science
• /
• v.34 no.2
• /
• pp.162-164
• /
• 2018

This study quantified the carbon storage and uptake by street trees in Seoul and explored suitable planting and management strategies. A systematic sampling model was used to select 50 plots to survey the structures of street trees. The average density and cover of street trees were approximately 5.8 trees/$100m^2$ and 12.1%, respectively. Trees with a dbh of less than 30 cm accounted for about 66.3% of the total number of trees surveyed. The total carbon storage and uptake by the street trees were approximately 103,641 t and 10,992 t/yr, respectively. The total carbon uptake equaled the amount of annual carbon emissions from driving of about 11,000 cars. Street tree planting and management strategies were proposed to enhance carbon uptake. They included multi-layered and multi-aged planting, securing ground and space for plant growth, and avoiding excessive tree pruning.

• Journal of KSNVE
• /
• v.7 no.1
• /
• pp.33-41
• /
• 1997

To cover a range of possible site conditions where the Korean standard nuclear power plant may be constructed, a range of generic site conditions is selected for geologic and seismologic evaluation. To envelop other Asian countries as well as the Korean peninsula, there is an attempt to increase the seismic level to 0.3g ground motions for the safe shutdown earthquake. The dynamic analyses of the reactor vessel internals and fuel assemblies are performed for the increased motions and the effect of seismic level on the response is investigated. Also the nonlinear response characteristics are discussed by comparing the loads between operating basis earthquake and safe shutdown earthquake excitations. The design adequacy of the reactor vessel internals and fuel assemblies for the increased seismic level is addressed.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.49 no.6
• /
• pp.21-33
• /
• 2007

Different vegetation indices from satellite images have been used for monitoring drought damages, and this study aimed to develop a drought index using NOAA/AVHRR NDVI(Normalized Difference Vegetation Index) and to analyze the temporal and spatial distribution of spring drought severity in North Korea from 1998 to 2001. A new drought index, DevNDVI(Deviation of NDVI), was defined as the difference between a monthly NDVI and average monthly NDVI at the same cover area, and the DevNDVI images at all years except for 2001 demonstrated the drought-damaged areas referred from various domestic and foreign publications. The vegetation of 2001 showed high vitality despite the least amount of rainfall among the target years, and the reason was investigated that higher temperature above normal average would shift the growing stages of plants ahead. Therefore, complementary methods like plant growth models or ground survey data should be adopted in order to evaluate drought-induced plant stress using satellite-based NDVI and to make up far the distortion induced by other environments than lack of precipitation.