• Korean Journal of Plant Taxonomy
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• v.44 no.3
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• pp.165-170
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• 2014

Most evergreen Quercus species are typical, dominant members of Korean evergreen forests. However, little is known about the distribution status of Q. myrsinifolia Blume there. To enhance our knowledge about their natural range in Korea, we conducted field surveys based on specimen records and an extensive literature search. We also determined their exact number as a first step in planning their conservation. The results indicated that these trees are strictly limited to Jin Island, and 169 mature individuals were the maximum number and occurred in only three subpopulations on that island. Previous misidentifications and perhaps mislabeled locations for plant specimens were the main reasons for earlier confusion about distribution. We believe that these results can provide guidance when making specific recommendations for management interventions. These discoveries also demonstrate the value in having reliable information about plant specimens in general. We also speculated about what makes this species particularly vulnerable to local extinction.

• Research in Plant Disease
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• v.26 no.3
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• pp.144-158
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• 2020

Quantitative reverse transcription PCR is used for gene expression analysis as the accurate and sensitive method. To analyze quantification of gene expression changes in apple plants, 10 housekeeping genes (ACT, CKL, EF-1α, GAPDH, MDH, PDI, THFs, UBC, UBC10, and WD40) were evaluated for their stability of expression during infection by Apple stem grooving virus (ASGV) or in cold-stress apple plant buds. Five reference-gene validation programs were used to establish the order of the most stable genes for ASGV as CKL>THFs>GAPDH>ACT, and the least stable genes WD40CKL>UBC10, and the least stable genes were ACT

• The Korean Journal of Mycology
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• v.44 no.1
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• pp.36-47
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• 2016

This study was conducted to evaluate five different strains of rhizobacterial isolates viz. PA1, PA2, PA4, PA5 and PA12 for biological control against Colletotrichum acutatum, C. coccodes, C. gloeosporioides, C. dematium, Botrytis cinerea, Rhizoctonia solani, Sclerotinia minor and Fusarium sp. In vitro inhibition assay was performed on three different growth mediums, potato dextrose agar (PDA), tryptic soy agar (TSA), and PDA-TSA (1:1 v/v) for the selection of potential antagonistic isolates. According to the result, isolate PA2 showed the highest inhibitory effect with 65.5% against C. coccodes on PDA and with 96.5% against S. minor on TSA. However, the same isolate showed the highest inhibition with 58.5% against C. acutatum on PDA-TSA. In addition, an in vivo experiment was performed to evaluate these bacterial isolates for biological control against fungal pathogens. Plants treated with bacteria were analyzed with phytopathogens and plants inoculated with phytopathogens were treated with isolates to determine the biological control effect against fungi. According to the result, all five isolates tested showed inhibitory effects against phytopathogens at various levels. Mode of action of these rhizobacterial isolates was evaluated with siderophore production, protease assay, chitinase assay and phosphate solubilizing assay. Bacterial isolates were identified by 16S rDNA sequencing, which showed that isolates PA1 and PA2 belong to Bacillus subtilis, whereas, PA4, PA5, and PA12 were identified as Bacilus altitudinis, Paenibacillus polymyxa and Bacillus amyloliquefaciens, respectively. Results of the current study suggest that rhizobacterial isolates can be used for the plant growth promoting rhizobacteria (PGPR) effect as well as for biological control of various phytopathogens.

• Korean Journal of Medicinal Crop Science
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• v.22 no.2
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• pp.140-146
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• 2014

This study was carried out to investigate the difference of the content of soil chemical components and growth characteristics in six years old ginseng affected by application of decomposing plant residues in paddy-converted field. The results show that aerial parts of ginseng are no difference between press cake (PC) 200 kg/10a and control but subterranean parts of ginseng PC 200 kg/10a, especially quantity related root fresh weight and tap root diameter, are statically about 1.6 times heavier and about 1.2 times thicker than the ginseng control. Furthermore, the survival rate of PC 200 kg/10a is 67.1% rise significantly compare with the control 50.7%. But compared with the PC 200 kg/10a and the PC 400 kg/10a, ginseng root growth and survival rate of PC 400 kg/10a get worse and that increase physiological disorder occurrence rate than PC 200 kg/10a. Even though there are no significant differences between the ginseng of decomposing plant residues except press cake treatment and the ginseng of control in growth characteristics, it does tend to increase the survival rate and decrease the physiological disorder occurrence rate in most fertilizer treatment except for RSC 2 ton/10a, RSC 4 ton/10a and RH 4 kL/10a. Noted that EC is highly increased and exceeded 1.7 ds/m in RSC 2 ton/10a, RSC 4 ton/10a and RH 4kL/10a. It would be caused physiological disorder in many ways and affected ginseng growth characteristics, survival rate.

• Journal of Ecology and Environment
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• v.43 no.4
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• pp.341-351
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• 2019

Background: Standing biomass, litter production, rate of litter decomposition, amount of litter on forest floor, and amount of soil organic carbon distribution were investigated from March 2016 to November 2018 in order to evaluate the ecosystem value through organic carbon distribution in the Pinus densiflora forest at Namsan, Seoul Metropolitan City. Results: The amount of organic carbon in the Pinus densiflora forest was 261.09 ton C ha^-1 during the research period, and fixed organic carbon in plant through net photosynthesis was 3.2 ton C ha^-1 year^-1. The organic carbon in plant was 62.77 ton C ha^-1 (24.04%), in litter on the forest floor was 3.65 ton C ha^-1 (1.40%), and in soil was 194.67 ton C ha^-1 (74.56%). The value of plant, litter on forest floor, and soil organic carbon distribution were each 6,277,000 won ha^-1, 365, 000 won ha^-1, and 19,467,000 won ha^-1. The value per ton of fixed organic carbon in plant through net photosynthesis was 320,000 won ha^-1 year^-1 and the value of ecosystem services stored in carbon in the Namsan forest ecosystem was about 26.1 million won ha^-1 for 3 years. Conclusions: The results of this study suggest that the pine forests of Namsan rapidly decompose leaves due to the high atmospheric temperature and accumulate a large amount of organic carbon in the soil to provide climate control regulatory service function.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.2
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• pp.1-19
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• 2023

In Korea, excessive vegetation in rivers made up of sand and gravel is emerging as a nationwide problem, which is attributed to increased spring precipitation and decreased annual precipitation. Therefore, this study was conducted for the purpose of identifying the effect of changes in precipitation patterns on river vegetation in Namcheon, Gyeongju, and analyzing the area of vegetation and ecological characteristics. As a result of the study, the amount of monthly precipitation in the summer of Namcheon decreased after 2007, and the area of vegetation increased continuously compared to the area of the sandbank. The proportion of naturalized plants increased steadily when precipitation continued to a level that did not cause flooding, but the area occupied by naturalized plants was small. Also, when the water level is maintained, the species diversity is low due to the dominance of a single species, and the dominant species was mainly native plants. Dominance of native plants inhibited the growth of naturalized plants, but the vegetation area increased even more. Therefore, it is necessary to manage the spread of vegetation itself rather than the division of native plants and naturalized plants in order to eliminate the active growth and prosperity of river vegetation. High water levels and continuous flooding caused by torrential rains in summer disturbed the plant communities, and vegetation formed afterwards was mainly native plants. Such flooding in river ecosystems is a positive factor for the emergence of native plants and over-formed vegetation communities, so it should be considered when establishing a vegetation management plan.

• The Plant Pathology Journal
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• v.22 no.3
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• pp.255-259
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• 2006

The pathogenicity to pear trees and other experimental hosts of the Apple stem grooving virus Korean isolate (ASGV-K) carried by a fungal vector, Talaromyces flavus was examined. ASGV-harboring T. flavus induced mild symptoms on virus-free pears. Symptom severity was intermediate between pears showing typical PBNLS and virus-free pears. Ten cultivars of Phaseolus vulgaris showed 35%-90% infectivity by direct infiltration into leaves and roots by ASGV-harboring T. flavus. Application of fungal cultures to soils showed 0%-70% infectivity depending on the P. vulgaris cultivar. Sap extracted from ASGV-infected Chenopodium quinoa induced similar symptoms on P. vulgaris at 25 days after inoculation. Similar symptoms were also detected on P. vulgaris which were inoculated with ASGV-harboring T.flavus. When healthy P. vulgaris leaves were challenged with sap extracted from P. vulgaris leaves infected with ASGV-harboring T. flavus, typical symptoms were observed. These data suggest that T. flavus mediates the transfer of ASGV to host plants.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.4
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• pp.437-442
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• 2010

Flow-accelerated corrosion (FAC) leads to thinning of steel pipe walls that are exposed to flowing water or wet steam. From experience, it is seen that FAC damage to piping at fossil and nuclear plants can result in outages that require expensive repairs and can affect plant reliability and safety. CHECWORKS have been utilized in domestic nuclear plants as a predictive tool to assist FAC engineers in planning inspections and evaluating the inspection data so that piping failures caused by FAC can be prevented. However, CHECWORKS may be occasionally ignore local susceptible portions when predicting FAC damage in a group of pipelines after constructing a database for all the secondary side piping in nuclear plants. This paper describes the methodologies that can complement CHECWORKS and the verifications of CHECWORKS prediction results using numerical analysis. FAC susceptible locations determined using CHECWORKS for two pipeline groups of a nuclear plant was compared with determined using the numerical-analysis-based FLUENT.

• Plant Journal
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• v.11 no.2
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• pp.45-51
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• 2015

In this paper, studied condenser operating management which is affecting power plants efficiency considering the cost of poor quality. Sea water temperature and condenser pressure have clear correlation in S power plants. As the sea water temperature changes, condenser pressure changed -1.7~+20 mmHg from design condenser pressure(38.1 mmHg). Use the heat rate correction curve from manufactory company, realized that efficiency and cost of poor quality changed 0.0201%, 12,830 won/h at Unit #1,2 but 0.0155%, 9,832 won/h when condenser pressure 1 mmHg rise. Also, checked that it is changed depend on seasonal corresponding operation, plant ageing and the point of preventive maintenance like overhaul maintenance. This study said if we considered complying with management range and planning overhaul maintenance, then it could help reducing operating maintenance losses minimum 2.5 billion won per 1 year (case : Unit #1, forty days maintenance).

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.1
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• pp.112-120
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• 2006

It is possible to divide the historical changes of slope revegetation in Japan into five periods as follows; 1) The early period after creation(1927-1948), 2) The spreading period of modern revegetation work with manpower(1947-1958), 3) The spreading period of rapid revegetation technique using exotic grasses with machineries(1959-1985${\dots}$), 4) The spreading period of rapid reforestation technique by fast growing species mainly using leguminous shrub species(1986-1995${\dots}$), 5) The developing period of nature restoration technique using endemic arborous species(1996-). Recently main purpose of slope revegetation has been developing from the erosion protection to the nature restoration in the current of the 5th period. It is said that the role of the Japanese Society of Revegetation Technology(JSRT) is critical to the history of slope revegetation in Japan. 'The tentative guidelines of slope nature restoration' was announced by JSRT in 2004. In the guidelines, it was proposed that the planning techniques of using suitable seeds/plants based on the preservation level at the each construction sites. Moreover, the use of soil seed bank is the new and important study theme in the field of nature restoration. Consequently, at present the importance of advanced monitoring methods for vegetation maintenance and plant sociologic survey to evaluate the plant succession is increasing. Finally, some critical concepts are necessary to develop the field of restoration in Korea as follows; 1) monitoring of constructed sites, 2) ensuring of biodiversity, 3) recognition of slow revegetation and mosaic arrangement in revegetation, 4) reuse and recycle on the construction sites, and 5) promotion of specialist.