Chulhyun Choi

Dr. Chulhyun Choi

orcid

Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 December 2018 in Forests
Verified
Journal Article
Open access
PDF file
JPJeon Soo Park
Jeon Soo Park
HSHak Sub Shin
Hak Sub Shin
CCChulhyun Choi
Chulhyun Choi
JLJunghyo Lee
Junghyo Lee
JKJinhee Kim
Jinhee Kim
A regional decline in the Korean fir (Abies koreana) has been observed since the 1980s in the subalpine region. To explain this decline, it is important to investigate the degree to which environmental factors have contributed to plant distributions on diverse spatial scales. We applied a hierarchical regression model to determine quantitatively the relationship between the abundance of Korean fir (seedlings) and diverse environmental factors across two different ecological scales. We measured Korean fir density and the occurrence of its seedlings in 102 (84) plots nested at five sites and collected a range of environmental factors at the same plots. Our model included hierarchical explanatory variables at both site-level (weather conditions) and plot-level (micro-topographic factors, soil properties, and competing species). The occurrence of Korean fir seedlings was positively associated with moss cover and rock cover but negatively related to dwarf bamboo cover. At the site level, winter precipitation was significantly and positively related to the occurrence of seedlings. A hierarchical Poisson regression model revealed that Korean fir density was negatively associated with slope aspect, topographic position index, Quercus mongolica cover, and mean summer temperature. Our results suggest that rising temperature, drought, and competition with other species are factors that impede the survival of the Korean fir. We can predict that the population of Korean fir will continue to decline in the subalpine, and only a few Korean fir will survive on northern slopes or valleys due to climate change.

12 January 2021 in Sustainability
Verified
Journal Article
Open access
PDF file
HSHyunjin Seo
Hyunjin Seo
CCChulhyun Choi
Chulhyun Choi
KLKyeongjun Lee
Kyeongjun Lee
DWDonggul Woo
Donggul Woo
Roads are notable and responsible for the loss of biodiversity and disruption of wildlife habitats connectivity. Wildlife crossing structures (WCS) help wildlife move between habitats by connecting fragmented habitats. Their effectiveness is affected by various factors. Here, to identify methods for improving the effectiveness of wildlife crossing structures, we controlled the effect of intrinsic factors, such as size, that are difficult to improve in an already installed area, and then, evaluated the differences in extrinsic factors using 12 landscape characteristics. Our results show that 18 wildlife crossing structures were selected with propensity-score (PS) matching method. The surrounding landscape characteristics differed between high-effectiveness wildlife crossing structures and low-effectiveness wildlife crossing structures. Particularly, there was a significant difference between the ‘statutory protected area’ and the ‘edge’ index of the morphological spatial pattern analysis among the landscape characteristic variables derived within 1 km2 of wildlife crossing structures. We empirically demonstrate that characteristics around highly effective WCS, statutory protected areas are widely distributed, and the ratio of edge of MSPA is low (within 1 km2). Therefore, an important outcome of our research is the demonstration that management of WCS itself is important, but conservation of surrounding habitats and landscape management plans are also significant.

1 May 2008 in Microelectronic Engineering
Verified
Journal Article
Closed access
JSJun-Ho Sung
Jun-Ho Sung
JYJeong-Su Yang
Jeong-Su Yang
BKBo-Soon Kim
Bo-Soon Kim
CCChulhyun Choi
Chulhyun Choi
MLMin-Woo Lee
Min-Woo Lee
BOBeom-Hoan O
Beom-Hoan O

31 March 2015 in Journal of the Korean Association of Geographic Information Studies
Verified
Journal Article
Closed access
CCChulhyun Choi
Chulhyun Choi

8 May 2025 in Remote Sensing
Verified
Journal Article
Open access
PDF file
Kyungil LeeKyungil Lee
Kyungil Lee
HBHaedam Baek
Haedam Baek
CCChulhyun Choi
Chulhyun Choi
SHSang-Hak Han
Sang-Hak Han
SPSeonyoung Park
Seonyoung Park
This study presents a national-scale mapping of Ecosystem Functional Groups (EFGs) in the Republic of Korea using the International Union for Conservation of Nature (IUCN) Global Ecosystem Typology (GET), a hierarchical classification system, integrated with spatial datasets, satellite imagery, and a random forest (RF) classifier. By incorporating locally relevant ecological data, the original typology was refined to resolve issues of overgeneralization and spatial overlap. The resulting map delineates 20 distinct ecosystem types, offering improved spatial accuracy and better alignment with the actual land extent. To evaluate the potential of EFG classification, the RF model was trained on seasonal satellite composites and environmental variables, achieving an overall accuracy of 80%. Elevation and temperature were found to be the most influential predictors, effectively distinguishing ecological patterns across diverse landscapes. This integrated approach supports consistent tracking of ecosystem changes and helps address the limitations of static or infrequently updated spatial datasets. The developed EFG map supports biodiversity conservation by providing a practical foundation for national spatial planning and contributing to the Red List of Ecosystems assessments, which is in line with the goals of the Global Biodiversity Framework.

23 October 2018 in Preprints.org
Verified
Preprint
Open access
PDF file
JPJeon Soo Park
Jeon Soo Park
HSHak Sub Shin
Hak Sub Shin
CCChulhyun Choi
Chulhyun Choi
JKJinhee Kim
Jinhee Kim
JLJunghyo Lee
Junghyo Lee
Regional declines of the Korean fir (Abies koreana) have been observed since the 1980s on the subalpine region. To explain this decline, it is fundamental to investigate the degree to which environmental factors have contributed to plant distributions on diverse spatial scales. We applied a hierarchical regression model to determine quantitatively the relationship between the abundance of Korean fir (seedlings) and diverse environmental factors across two different ecological scales. We measured Korean fir density and the occurrence of its seedlings in 102 (84) plots nested at five sites and collected a range of environmental factors at the same plots. Our model included hierarchical explanatory variables at both site-level (weather conditions) and plot-level (micro-topographic factors, soil properties, and competing species). The occurrence of Korean fir seedlings was positively associated with moss cover and rock cover but negatively related to dwarf bamboo cover. On site-level, winter precipitation was significantly positively related to the occurrence of seedlings. A hierarchical Poisson regression model revealed that Korean fir density were negatively associated with slope aspect, topographic position index, Quercus mongolica cover, and mean summer temperature. Our results suggest that drought and competition with other species are factors which halt the survival of Korean fir. We can predict that the population of Korean fir will continue to decline on the Korean Peninsula due to rising temperatures and seasonal drought, and only a few Korean fir will survive on northern slopes or valleys where competition with dwarf bamboo and Q. mongolica can be avoided.