• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.3
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• pp.191-200
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• 2013

This study was conducted to examine the geographic variation of bud phenology of Zelkova serrata provenances. Data were collected from Gangneung, Yilmsil, Hwaseong and Jinju plantations which were parts of the 6 provenance trials established by Korea Forest Research Institute in 2009. The 16 provenances were included in these trials. The starting date of bud burst and finishing date of leaf expansion were investigated from April to May every other day. The four geographic factors and fifteen climatic factors of the test sites and provenances were considered in this study. Canonical correlation analysis was conducted to examine the major factors affecting the bud phenology between test sites and provenances. The study results suggested that the major factors affecting the timing of bud burst were the differences of extremely high temperature (March-October), annual mean temperature, mean temperature (March-October), extremely high temperature (July-August) and mean humidity (June-October) between test site and provenance. The provenances with lower mean or high temperature than those of plantation showed the earlier bud burst and leaf expansion. It showed a typical north-south or low-high temperature cline. Finally, we discussed the implication of the tree breeding program of Z. serrata based on these results.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.3
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• pp.109-119
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• 2016

This study was conducted to analyze the effect of yearly changes in growing degree days (GDD) on the potential distribution and growth of Quercus mongolica in Korea. Annual tree-ring growth data of Quercus mongolica collected by the $5^{th}$ National Forest Inventory were first organized to identify the range of current distribution for the species. Yearly GDD was calculated based on daily mean temperature data from 1951 to 2010 for counties with current distribution of Q. monglica. When tree-ring growth data were analyzed through cluster analysis based on similarity of climatic conditions, seven clusters were identified. Yearly GDD based on daily mean temperature data of each county were calculated for each of the cluster to predict the change of potential distribution. Temperature effect indices were estimated to predict the effect of GDD on the growth patterns. In addition, RCP 4.5 and RCP 8.5 of climate change scenarios were adopted to estimate yearly GDD and temperature effect indices from 2011 to 2100. The results indicate that the areas with low latitude and elevation exceed the upper threshold of GDD for the species due to the increase of mean temperature with climate change. It was also predicted that the steep increase of temperature will have negative influences on tree-ring growth, and will move the potential distribution of the species to areas with higher latitude or higher elevation, especially after the year of 2050. The results of this study are expected to provide valuable information necessary for estimating local growth characteristics and for predicting changes in the potential distribution of Q. mongolica caused by climate change.

• Spatial Information Research
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• v.16 no.4
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• pp.467-478
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• 2008

This study analyzes the spatial and temporal variability of temperature ($^{\circ}C$) and precipitation (mm) in Seoul, Korea. The temperature and precipitation data were measured at 31 automatic weather stations (AWSs) in Seoul for 10 years from 1997 to 2006. In this study, inverse distance squared weighting (IDSW) was applied to interpolate the non-measured spaces. To estimate the temperature and precipitation variability, the mean values and frequencies of hot and cold days were examined. The maximum and minimum temperatures were $32.80^{\circ}C$ in 1999 and $-19.94^{\circ}C$ in 2001, respectively. The year 2006 showed the highest frequency of hot temperatures with 79 hot days, closely followed by 2004 and 2005. The coldest year was in 2001 with 105 cold days. The annual mean temperature and precipitation increased by about $1^{\circ}C$ and 483mm during the 10-year period, respectively. The temperature variability differed between high-elevation forested areas and low-elevation residential areas. However, the precipitation variability showed little relation with the topography and land use patterns.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.5
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• pp.116-127
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• 2014

The studies were carried out to process one cycle for a day to the large section tunnel lining concrete. Climatic characteristics of the tunnel inside are changed, when the temperature of the concrete placement is low, the mold remove time is increased that the heat of hydration speed be delayed because affects the strength development, to compensate for this, after installing the curing sheet on both sides of the steel form and installation of tunnel entrance, when it comes to providing the additional heat source of $28{\pm}2^{\circ}C$ therein, it was to be achieved early strength development control standards (4.5MPa) presented as a crack control scheme or more, thus, It was able to remove after age of 14hr from mold. On the other hand, under the conditions of $10{\pm}1^{\circ}C$ that a natural curing temperature in the tunnel, it was analyzed must ensure the curing time of 36hr or more after concrete placement. Throughout this study, the concrete strength development and the temperature in the early-age concrete, it can find that reverify the curing temperature is greatly affected, even concrete fly ash is mixed 10%, if it is possible to raise the surface temperature for a predetermined time, is not a problem in the early strength development.

• The Korean Journal of Physiology
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• v.3 no.1
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• pp.19-28
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• 1969

Skin temperatures on 10 sites and rectal temperature at every 10 minutes, oxygen consumption at every 20 minutes were measured on 18 male subjects (ages between 14 and 47 years) after exposure to cold air at $15^{\circ}C$ for two hours in a climatic room. Total body fat measured by means of a skinfold method and ratio of body surface area (S) to body volume (V), S/V, were utilized as basis of observations. Surface area was calculated after DuBois equation and body volume was calculated by our original formula. In influencing on the heat loss from the body core to the cold environment, % fat showed inverse relations, whereas, S/V ratio showed direct relations. Thus these two factors acted antagonistically on the body heat loss. Local skin temperatures showed negative correlations with skinfold thickness on the same site, nemaly, on chest, r=-.567; on back, r=-.507; and on upper arm, r=-.353. The other 7 skin sites showed low correlations with % fat. Minimum mean weighted skin temperature (MWST) showed a negative correlation (r=-.443) with % fat, and showed no correlation with S/V ratio. Oxygen consumption in the cold air at $15^{\circ}C$ increased from the first measurement at 20 minutes after exposure and maintained the same increasing trend up to 120 minutes. ${\Delta}T_R$ was greater in tile lean subjects who showed a greater % change in oxygen consumption. The antagonistic actions of % fat and S/V ratio on the heat loss were manifested by observations as follows: minimum rectal temperature was higher In fat subjects (r=.600) and lower in subjects with a greater S/V ratio (=-.582), ${\Delta}T_R$ was smaller in fat subjects (r=-.738) and greater in subjects with a greater S/V ratio (r=.618). Temperature difference between body core and skin surface (minimum rectal temperature minus minimum MWST) showed a positive correlation with % fat (r=.600) and a negative correlation with S/V ratio (r=-.881). Decrease in the mean body temperature and heat debt, respectively, showed negative correlations with % fat and positive correlations with S/V ratio.

• Journal of Animal Science and Technology
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• v.62 no.2
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• pp.227-238
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• 2020

Use of raw feedstuffs for livestock is limited by low digestibility. Recently, fermentation of feedstuffs has been highlighted as a new way to improve nutrient absorption through the production of organic acids using inoculated microorganisms, which can also play a probiotic role. However, standard procedures for feedstuff fermentation have not been clearly defined because the process is influenced by climatic variation, and an analytical standard for fermented feedstuffs is lacking. This study aimed to evaluate the microbiological and biochemical changes of feedstuffs during fermentation at temperatures corresponding to different seasons (10℃, 20℃, 30℃, and 40℃). We also investigated the effects of yeast, lactic acid bacteria (LAB), and Bacillus spp. on fermentation and determined the results of their interactions during fermentation. The viable cells were observed within 8 days in single-strain fermentation. However, when feedstuffs were inoculated with a culture of mixed strains, LAB were predominant at low temperatures (10℃ and 20℃), while Bacillus spp. was predominant at high temperatures (30℃ and 40℃). A significant drop in pH from 6.5 to 4.3 was observed when LAB was the dominant strain in the culture, which correlated with the concentrations of lactic acid. Slight ethanol production was detected above 20℃ regardless of the incubation temperature, suggesting active metabolism of yeast, despite this organism making up a marginal portion of the microbes in the mixed culture. These results suggested that fermentation temperature significantly affects microbiological profiles and biochemical parameters, such as pH and the lactic acid concentration, of fermented feedstuffs. Our data provide valuable information for the determination of industrial standards for fermented feedstuffs.

• The Korean Journal of Mycology
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• v.32 no.2
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• pp.71-78
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• 2004

This study was conducted to investigate the diversity and occurrence frequency of ectomycorrhizal fruit bodies by planting sites from June 2000 to October 2001. A total of 3 classes 3 subclasses 8 orders 22 families 41 genera and 72 species (including two varieties) including saprophytic and ectomycorrhizal fungi was investigated. The mushrooms are classified into 9 families 21 genera and 48 species in Agaricales, 5 families 11 genera and 13 species in Aphllophorales, 3 families 3 genera and 4 species in Heterobasidiomycetes and 5 families 6 genus and 7 species in Gasteromycetdae. A total of 7 families 11 genera 30 species (2,451 ea.) of ectomycorrhizal mushroom was investigated. The occurrence frequency of mushrooms was 1,225, 179 and 130 times for Laccaria vinaceoavellanea, Amanita longistriata and Laccaria amethystea, respectively. The mushroom occurrence of ectomycorrhizal fungi was closely related to climatic conditions such as high air temperature, relative humidity and lots of rainfall from July to August. Diversity and distribution of ectomycorrhizal fungi by plots were very different because of variable local environments and different host plants in experimental plots. Laccaria vinaceoavellanea has showed very low host range of plant specificity because of mushroom occurrence in only Quercus sp. and Amanita longistriata, Russula bella and Inocybe sp. have showed wide host range of plant specificity because of mushroom occurrence in coniferous and broadleaved trees. The environment which has a favorable influence of mushroom occurrence was soil pH, organic matter and T/N ratio of soil enviromental and humidity of climatic environment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.6
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• pp.710-717
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• 1996

To obtain the basic informations on the farm cultivation of Eleutherococcus senticosus Max., field survey of the native habitat in Mt. Deokyu such as weather, soils, vegetation and growth was carried out. The habitat of E. senticosus is situated at 127$^{\circ}$ 45'E, 35$^{\circ}$ 52' N in Mt. Deokyu where the elev-tion ranges from 1,050 to 1,300 meters above the sea level. Mean annual temperature forecasted around the habitat was 5.8$^{\circ}C$, mean maximum temperature in August, 24.6$^{\circ}C$ ; mean minimum temperature in January, -13.5$^{\circ}C$ and relative humidity during the growth periods, over 95%. To divide the area according to climatic conditions was classified cool temperature and humid rain forest zone. In another view, it belonged to deciduous broad-leaf forest zone and soil texture was sandy loam with dark brown gravels. Acidity and P$_2$O$_{5}$ content of soil represented pH 5.2～5.6 and 10ppm, respectively. The growth of E. senticosus was poor under the low light intensity(relative 20% of full sun-light) at the growing place of the habitat and the propagation was conducted by root sucker. The natural vegetation was consisted of big trees, 3 species; shrubs, 8 species and herbs, 4 species.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s02
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• pp.34-44
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• 1989

The stability of rice cultivation in Korea is largely depended on climatic conditions, especially, low temperature at the period of early growth stage and after heading. The improvement of cold tolerant varieties and appropriate cultural practices in rice are very effective to minimize the cold damage. This paper is summarized the mechanism and counterplans of cold injury of rice plants. The paddy area having commonly cold injury in Korea is approximately 15, 522ha in 1,709 sites on the national scale. The cold damage at seedling stage in nursery bed appeared to poor germination, leaf discoloration, dead seedlings and seedling rot ect.. At the vegetative stage, the decreased tiller number due to poor rooting and the delayed heading caused by slow growth and panicle differentiation are commonly showed. The cold injury at early reproductive stage appeared to the degeneration of spikelets and rachis - branches, while that at meiosis stage showed to increased sterility due to poor development of pollen and shortened panicle length with delaying heading, therefore the grain yield is largely decreased. The cold damage at heading and ripening stages showed to poor pollination and fertilization, low panicle exsertion, poor grain filling and finally grain quality became low. To minimize the cold injury to rice plants by low temperature, following counterplans would be recommonded ; Improvement of the cold toelrant rice varieties for the regions of midmountains and alpines. Raising healthy seedlings at upland nursery beds and by using of growth regulators such as ABA, Fuchiwang and Tachiace. Soil improvement and organic matter application to reduce cold damage by increasing water and fertilizer holding capacities in the paddy field having commonly cold water and in the place where cold damage is regularly occurred. Appropriate fertilization for raising healthy rice plants to tolerate under low temperature condition. Water management to increase water temperature in the paddy such as depth watering, round channels and polyethylene tubes around the field. Establishment of the optimum cultivation time of rice based on minimum, mean and maximum temperatures at different regions with appropriate rice varieties.

• Journal of Forest and Environmental Science
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• v.38 no.2
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• pp.110-121
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• 2022

Leaf functional traits widely have been used to understand the environmental controls of resource utilization strategy of plants along the environmental gradients. By using key leaf functional traits, we quantified the relationships between leaf traits and local climate throughout the distributional range of Rhododendron caucasicum Pall. in eastern and western Georgian mountains (the South Caucasus). Our results revealed, that all traits showed high levels of intraspecific variability across study locations and confirmed a strong phenotypic differentiation of leaf functional variation along the east-west longitudinal gradient in response to the local climate; out of the explored climatic variables, the moisture factors related to precipitation and number of precipitation and dry days for winter and growth seasons were more strongly related to leaf trait variation than the elevation and air temperature. Among studied leaf traits, the leaf specific area (SLA) showed the highest level of variability indicating the different resource utilization strategies of eastern and western-central Rh. caucasicum individuals. High SLA leaves for western-central Caucasian individuals work in relatively resource-rich environments (more humid in terms of precipitation amount and the number of precipitation days in winter) and could be explained by preferential allocation to photosynthesis and growth, while eastern Caucasian samples work in resource-poor environments (less humid in terms of precipitation amount and the number of precipitation days in winter) and the retention of captured resources is a higher priority appearing in a low SLA leaves. However, more evidence from a broader study of the species throughout its distribution range by including additional environmental factors and molecular markers are needed for firmer conclusions of intraspecific variability of Rh. caucasicum.