• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.4
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• pp.232-245
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• 2017

In this study, the high-resolution numerical simulation results considering landuse characteristics are analyzed by using single layer Urban Canopy Model (UCM) in Weather Research Forecast (WRF). For this, the impact of urban parameters such as roughness length and anthropogenic heat in UCM is analyzed. These values are adjusted to Seoul metropolitan area in Korea. The results of assessment are verified against observation from surface and flux tower. Forecast system equipped with UCM shows an overall improvement in the simulations of meteorological parameters, especially temperature at 2 m, surface sensible and latent heat flux. Major contribution of UCM is appreciably found in urban area rather than non-urban. The non-urban area is indirectly affected. In simulated latent heat flux, applying UCM is possible to simulate the change similarly with observations on urban area. Anthropogenic heat employed in UCM shows the most realistic results in terms of temperature and surface heat flux, indicating thermodynamic treatment of UCM could enhance the skills of high resolution forecast model in urban and non-urban area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.21 no.3
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• pp.103-111
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• 2016

Seasonal dynamics of kelp forest-forming algae, Ecklonia cava population formed following the large-scale disturbance by Typhoon 'Bolaven' in August 2012 were investigated in Jeju Island, Korea. Morphological characteristics, recruits density, mortality rate, total density and biomass were monitored bimonthly from June 2013 to June 2015. Total and longest blade lengths, and individual weight of E. cava showed distinct seasonal trends. Stipe length increased from winter to spring, but did not show increase or reduced from summer to autumn. This indicates that morphological characteristics of E. cava are mainly affected by the change of blades. The optimal temperature for E. cava growth was about $15-18^{\circ}C$ during winter to spring while the growths were inhibited at the water temperature above $20^{\circ}C$ during summer. E. cava exhibited very low recruitment during spring-summer. However, high recruitment was observed on April 2015 when canopy cover was very low due to low density. This indicates that recruitment of E. cava was controlled not by seasonal effects but by physical factors such as canopy and space. The mortality rate of juvenile plants was highest due to their unstable settlement. By June 2015, 34 months after the disturbances, E. cava was almost recovered to the pre-disturbance population size structure. These results suggest that recovery of kelp forest following the large-scale disturbance requires a considerable period of time (more than three years). This study should provide valuable ecological information on management, restoration and protection of kelp species.

• Korean Journal of Remote Sensing
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• v.40 no.4
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• pp.397-418
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• 2024

The Land Surface Temperature (LST) is a crucial parameter in identifying drought. It is essential to identify how LST can increase its accuracy, particularly in mountainous and hill areas. Increasing the LST accuracy can be achieved by applying early data processing in the correction phase, specifically in the context of topographic correction on the Lambertian model. Empirical evidence has demonstrated that this particular stage effectively enhances the process of identifying objects, especially within areas that lack direct illumination. Therefore, this research aims to examine the application of the Lambertian model in estimating LST using the Multi-Channel Method (MCM) across various physiographic regions. Lambertian model is a method that utilizes Lambertian reflectance and specifically addresses the radiance value obtained from Sun-Canopy-Sensor(SCS) and Cosine Correction measurements. Applying topographical adjustment to the LST outcome results in a notable augmentation in the dispersion of LST values. Nevertheless, the area physiography is also significant as the plains terrain tends to have an extreme LST value of ≥ 350 K. In mountainous and hilly terrains, the LST value often falls within the range of 310-325 K. The absence of topographic correction in LST results in varying values: 22 K for the plains area, 12-21 K for hilly and mountainous terrain, and 7-9 K for both plains and mountainous terrains. Furthermore, validation results indicate that employing the Lambertian model with SCS and Cosine Correction methods yields superior outcomes compared to processing without the Lambertian model, particularly in hilly and mountainous terrain. Conversely, in plain areas, the Lambertian model's application proves suboptimal. Additionally, the relationship between physiography and LST derived using the Lambertian model shows a high average R² value of 0.99. The lowest errors(K) and root mean square error values, approximately ±2 K and 0.54, respectively, were achieved using the Lambertian model with the SCS method. Based on the findings, this research concluded that the Lambertian model could increase LST values. These corrected values are often higher than the LST values obtained without the Lambertian model.

• Korean Journal of Environment and Ecology
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• v.34 no.4
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• pp.318-333
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• 2020

The Nakdong-Jeongmaek extends north and south from Taebaek-si of Gangwon-do to Busan metropolitan city and includes a wide range of forest zone from temperate to the warm-temperature forest. The purpose of this study was to analyze the vegetation structural characteristics of the Quercus mongolica-dominant community, which was distributed in the largest area in Baekdudaegan and Jeongmaek, by region and communities in the Nakdong-Jeongmaek. For the study, a representative 6 sites were selected: Baekbyeongsan, Chilbosan, Baegamsan, Unjusan, Goheonsan, and Gudeoksan. The survey of the 6 sites showed that the canopy had over 85% the importance percentage of Quercus mongolica. In the understory, Rhododendron schlippenbachii, Fraxinus sieboldiana, etc. were located and Fraxinus sieboldiana, Lespedeza maximowiczii, Tripterygium regelii and so on were found in the shrub. The importance percentage of 4 communities of Quercus mongolica, which were separated by TWINSPAN, in the canopy was more than 80%, and the dominant species in the understory and shrub were the same. Currently, Quercus mongolica has been identified as the understory following the canopy, and the Quercus mongolica-dominant community is expected to continue unless there are external factors. In the temperate forest regions in Korea, Quercus spp.and Carpinus laxiflora form the major forest physiognomy in the natural forest state. Based on these characteristics, the Quercus mongolica-dominant community on the ridge of the Nakdong-Jeongmaek is considered to have characteristics of temperate forests in Korea. The Quercus mongolica community is a representative cool-temperate deciduous forest and known as a climatic climax in the upper section of the mountains in the Korean Peninsula. Trees of the same species should be distributed at each layer to maintain the dominant species' status in the canopy's climax forest. Therefore, the Quercus mongolica community is considered the climax forest in the ridge of the Nakdong-Jeongmaek.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.366-376
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• 2023

This study was conducted to develop a model for predicting the growth of kimchi cabbage using image data and environmental data. Kimchi cabbages of the 'Cheongmyeong Gaual' variety were planted three times on July 11th, July 19th, and July 27th at a test field located at Pyeongchang-gun, Gangwon-do (37°37' N 128°32' E, 510 elevation), and data on growth, images, and environmental conditions were collected until September 12th. To select key factors for the kimchi cabbage growth prediction model, a correlation analysis was conducted using the collected growth data and meteorological data. The correlation coefficient between fresh weight and growth degree days (GDD) and between fresh weight and integrated solar radiation showed a high correlation coefficient of 0.88. Additionally, fresh weight had significant correlations with height and leaf area of kimchi cabbages, with correlation coefficients of 0.78 and 0.79, respectively. Canopy coverage was selected from the image data and GDD was selected from the environmental data based on references from previous researches. A prediction model for kimchi cabbage of biomass, leaf count, and leaf area was developed by combining GDD, canopy coverage and growth data. Single-factor models, including quadratic, sigmoid, and logistic models, were created and the sigmoid prediction model showed the best explanatory power according to the evaluation results. Developing a multi-factor growth prediction model by combining GDD and canopy coverage resulted in improved determination coefficients of 0.9, 0.95, and 0.89 for biomass, leaf count, and leaf area, respectively, compared to single-factor prediction models. To validate the developed model, validation was conducted and the determination coefficient between measured and predicted fresh weight was 0.91, with an RMSE of 134.2 g, indicating high prediction accuracy. In the past, kimchi cabbage growth prediction was often based on meteorological or image data, which resulted in low predictive accuracy due to the inability to reflect on-site conditions or the heading up of kimchi cabbage. Combining these two prediction methods is expected to enhance the accuracy of crop yield predictions by compensating for the weaknesses of each observation method.

• Horticultural Science & Technology
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• v.16 no.3
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• pp.350-351
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• 1998

This study was conducted to investigate the effect of reflective film(RF) mulching on the growth and flowering of snapdragon 'Fujinoyuki' in greenhouse cultivation. On the spectroradiometry of mulching materials in the wavelength zone of 300nm to 1100nm, 85% of total light source was reflected from RF, while over 95% was absorbed into black polyethylene film(BL). Under plant canopy, light, air temperature, and leaf temperature were higher on the RF mulching than BL, but soil temperature and soil heat flux were higher under the BL. Primary plant growth such as dry weight, stem hardness, lodging, and transpiration was superior when using RF mulching. RF mulching accelerated the plants to bloom about 12 days earlier with admirable cut flower quality.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.3
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• pp.149-163
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• 2004

Evapotranspiration (ET) is a critical component of the hydrologic cycle which influences economic activities as well as the natural ecosystem. While there have been numerous studies on ET estimation for homogeneous areas using point measurements of meteorological variables, monitoring of spatial ET has not been possible at landscape - or watershed - scales. We propose a site-specific application of the land surface model, which is enabled by spatially interpolated input data at the desired resolution. Gyunggi Province of South Korea was divided into a regular grid of 10 million cells with 30m spacing and hourly temperature, humidity, wind, precipitation and solar irradiance were estimated for each grid cell by spatial interpolation of synoptic weather data. Topoclimatology models were used to accommodate effects of topography in a spatial interpolation procedure, including cold air drainage on nocturnal temperature and solar irradiance on daytime temperature. Satellite remote sensing data were used to classify the vegetation type of each grid cell, and corresponding spatial attributes including soil texture, canopy structure, and phenological features were identified. All data were fed into a standalone version of SiB2(Simple Biosphere Model 2) to simulate latent heat flux at each grid cell. A computer program was written for data management in the cell - based SiB2 operation such as extracting input data for SiB2 from grid matrices and recombining the output data back to the grid format. ET estimates at selected grid cells were validated against the actual measurement of latent heat fluxes by eddy covariance measurement. We applied this system to obtain the spatial ET of the study area on a continuous basis for the 2001-2003 period. The results showed a strong feasibility of using spatial - data driven land surface models for operational monitoring of regional ET.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.2
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• pp.164-173
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• 2018

Elevated atmospheric carbon dioxide concentration ($CO_2$) is a major component of climate change, and this increase can be expected to continue into the crop and food security in the future. In this study, Soil-Plant-Atmosphere-Research (SPAR) chambers were used to examine the effect of elevated $CO_2$, temperature, and drought on the canopy architecture and concentration of macronutrients in potatoes (Solanum tuberosum L.). Drought stress treatments were imposed on potato plants 40 days after emergence. Under AT+2.8C700 (30-year average temperature + $2.8^{\circ}C$ at $700{\mu}mol\;mol^{-1}$ of $CO_2$), at maximum leaf area, elevated $CO_2$, and no drought stress, a significant increase was observed in both the aboveground biomass and tuber, and for the developmental stage. Even though $CO_2$ and temperature had increased, AT+2.8C700DS (30-year average temperature + $2.8^{\circ}C$ at $700{\mu}mol\;mol^{-1}$ of $CO_2$ under drought stress) under drought stress showed that the leaf area index (LAI) and dry weight were reduced by drought stress. At maturity, potatoes grown under $CO_2$ enrichment and no drought stress exhibited significantly lower concentrations of N and P in their leaves, and of N, P, and K in tubers under AT+2.8C700. In contrast, elevated $CO_2$ and drought stress tended to increase the tuber Mg concentration under AT+2.8C700DS. Plants grown in AT+2.8C700 had lower protein contents than plants grown under ATC450 (30-year average temperature at $400{\mu}mol\;mol^{-1}$ of $CO_2$). However, plants grown under AT+2.8C700 showed higher tuber bulking than those grown under AT+2.8C700DS. These findings suggest that the increase in $CO_2$ concentrations and drought events in the future are likely to decrease the macronutrients and protein concentrations in potatoes, which are important for the human diet.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.155-170
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• 2016

This study established the definition of invasive disturbance species for a sustainable management and biodiversity, and derived the influence factors caused by the species. To define the species, the paper reviewed similar words such as alien species and invasive species, using standard definitions. Also reviewed the results of recent research on the factors of the species. The paper defined the invasive disturbance species as an species whose establishment and spread threaten ecosystems, habitats or species with economic or environmental harm including native and non-native. Through the reviews, The factors were classified as geographic (altitude, slope, and soil, etc.), climate (temperature, precipitation, climate change, etc.) and, anthropogenic (land use, population, road, and human activity, etc.), and species & vegetation structure (species property, local-species richness, and canopy, etc.). Especially, human activity such as urbanization and highways may be associated with both higher disturbance and higher propagule pressure. In the further study, it is required development of mitigation strategies and vegetation structure model against invasive disturbance species in urban forest based on this study.

• Journal of Ecology and Environment
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• v.38 no.1
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• pp.1-14
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• 2015

Whilst it is clear that increasing temperatures from global environmental change will impact the positions of alpine treelines, it is likely that a range of regional and local scaled factors will mediate the overall impact of global scale climate drivers. We summarized 12 categories of abiotic and biotic factors as 4 groups determining treeline positions. First, there are global factors related to climate-induced growth limitation and carbon limitation. Second, there are seven regional and local factors related to treeline dynamics including frost stress, topography, water stress, snow, wind, fire and non-fire disturbance. Third, species-specific factors can control treeline dynamics through their influence on reproduction and life history traits. Fourth, there are positive feedbacks in structuring the dynamics of treelines. Globally, the commonly accepted growth limitation hypothesis is that growth at a treeline is limited by temperature. Meanwhile, positive feedbacks between canopy cover and tree establishment are likely to control the spatial pattern and temporal dynamics of many treelines. The presence of non-linear dynamics at treelines has implications for the use of treelines as barometers of climate change because the lagged responses and abrupt shifts inherent in non-equilibrium systems may combine to mask the overall climate trend.