Estimation and Validation of Taper Equations for Three Major Coniferous Species in Gangwon and North Gyeongsang Provinces of South Korea

Daesung Lee,Yeongwan Seo2,Jungho Lee,Jungkee Choi 강원대학교 산림과학연구소 2017 Journal of Forest Science Vol.33 No.4

This study was carried out to estimate the parameters of stem taper functions, to figure out the best taper model by species, and to compare with previous studies by species, targeting on the stemmed tree samples collected from the Korean red pine (Pinus densiflora), Korean white pine (Pinus koraiensis), and Japanese larch (Larix kaempferi ) stands in Gangwon and North Gyeongsang provinces of South Korea. The seven widely used models were applied in this study, and Muhairwe 1999 model for Korean red pine and Korean white pine and Kozak 2002 model for Japanese larch were evaluated as the best model for each species according to the fit statistics and the predicted stem form comparison. In addition, the predicted diameter was suitably fitted when comparing the previous studies, and the values were more appropriate following stem taper according to neiloid, paraboloid, and cone parts by species. Consequently, the estimation of this study was considered to represent the stem taper well. When comparing stem taper of three species, the diameter was largest in Korean white pine. Overall, the taper models of this study are judged to be useful for estimating stem form and volume computation of Korean red pine, Korean white pine, and Japanese larch.

Effect of Aroma Therapy on the Stress Alleviation and Job Satisfaction of Taxi Drivers

Seo, Yeongwan,Kim, Soyeon,Jeong, Sooncheol,Lee, Daesung,Choi, Jungkee Institute of Forest Science 2020 Journal of Forest Science Vol.36 No.4

This study was carried out to find the effects of aromatherapy using natural fragrance on reducing stress and improving job satisfaction of transportation workers in the taxi industry. A total of 120 workers were divided into the experimental group and the control group according to the inhalation of the fragrance and tested for 2 weeks. After 2 weeks, the difference of emotional change, stress analysis, and evaluation of job satisfaction according to aromatherapy were compared between the two groups. The result showed that the experimental group had a higher interest in scent products than the control group and that they wanted to encounter a lot of real scents, indicating that aromatherapy caused positive interest in general scent likability. In addition, the experimental group said that the inhalation of fragrance would refresh the feeling of the passengers in the vehicle and smoothly communicate with the passengers. Especially, it showed a significant difference between the two groups in terms of tension relief, pleasure and good mood by inhalation of fragrance, indicating the positive effect on job satisfaction.

Growth Analysis of Red Pine (Pinus densiflora) by Stem Analysis in the Eastern Region of Korea

Yeongwan Seo,Daesung Lee,Jungkee Choi 강원대학교 산림과학연구소 2015 Journal of Forest Science Vol.31 No.1

The study was performed to analyze the growth of the red pine (Pinus densiflora) in the Eastern Region of Korea. Stem profile data from a total of 8 dominant trees of which each tree represents its site were collected and used for the analysis. The stem volumes were calculated using Smalian’s formula and much higher than the ones by Korea Forest Research Institute in larger than dbh 40 cm. The total bark volumes were more proportionally related to dbh and stem volume than to height and age. The bark thickness and volume decreased as relative height increases but increased as relative dbh increased. The average PAI of dbh and height reached the highest at 0.8 cm/yr (age 15) and at 0.45 m/yr (age 30) respectively, while the average PAI of volume steadily tended to increase up to age 80. The growth percentages of dbh, height and volume tended to decrease with age and volume growth percentage was higher than dbh and height.

Growth Analysis of Red Pine (Pinus densiflora) by Stem Analysis in the Eastern Region of Korea

Seo, Yeongwan,Lee, Daesung,Choi, Jungkee Institute of Forest Science 2015 Journal of Forest Science Vol.31 No.1

The study was performed to analyze the growth of the red pine (Pinus densiflora) in the Eastern Region of Korea. Stem profile data from a total of 8 dominant trees of which each tree represents its site were collected and used for the analysis. The stem volumes were calculated using Smalian's formula and much higher than the ones by Korea Forest Research Institute in larger than dbh 40 cm. The total bark volumes were more proportionally related to dbh and stem volume than to height and age. The bark thickness and volume decreased as relative height increases but increased as relative dbh increased. The average PAI of dbh and height reached the highest at 0.8 cm/yr (age 15) and at 0.45 m/yr (age 30) respectively, while the average PAI of volume steadily tended to increase up to age 80. The growth percentages of dbh, height and volume tended to decrease with age and volume growth percentage was higher than dbh and height.

Comparing forest structures in the border areas of the demilitarized zone of South Korea

Seo, Yeongwan,Lee, Daesung,Cha, Dusong,Choi, Jungkee Sage Publishing 2017 Forest Science And Technology Vol.13 No.1

A Study on Preference and Behavior of Forest Path Users

Seo, Yeongwan,Jung, Sanghyun,Jeong, Sooncheol,Kim, Soyeon,Choi, Jungkee Institute of Forest Science 2021 Journal of Forest Science Vol.37 No.3

This study was conducted to grasp users' preferences and behavior of forest paths and to provide basic data for forest path construction in the future. Among forest path users, males and females over 20 years old were surveyed on forest path preferences, motives for visiting, using time and distance, companions, and sources for obtaining information on forest paths. A total of 587 people participated in the questionnaire, and cross-analysis was conducted simultaneously using the SPSS statistical program. In analyzing the preference of forest paths, it was found that male and the general public preferred trekking path for activities while female and foresters preferred forest path for relaxation and healing (p<0.05). As for the motives for visiting forest paths, the response that they visited for a walk/rest was the highest in gender, occupation, and age group. As for the number of annual visits, less than 5 was the highest in overall, and foresters tended to visit forest path more often than the general public, and the number of visits to the forest paths increased with age (p<0.01). The most common route to acquire information about forest paths is the Internet, while the Internet use is relatively low in those over 60s (p<0.05). The response ratio of accompanying their family in visiting forest paths were the highest, while the response in their 20s and 60s was the most in accompanying their friends (p<0.05).

Comparison of Growth and Allometric Change of Stand and Dominant Trees in Pinus koraiensis Plantation over 34 Years

Seo, Yeongwan,Lee, Daesung,Chhorn, Vireak,Choi, Jungkee Institute of Forest Science 2018 Journal of Forest Science Vol.34 No.3

This study was conducted to find out the growth pattern of Pinus koraiensis plantation over 34 years, focusing on DBH, height, basal area and allometric change. Total increment (TI), mean annual increment (MAI) and correlation coefficient were calculated and compared with stand and dominants. Total increment and mean annual increment of both DBH and height of dominants were bigger than those of stand. The difference was apparently shown bigger in DBH than height. Unlike DBH and height the total increment and mean annual increment of basal area per hectare of dominants were distinctively smaller than those of stand. Furthermore MAI of dominant was increasing until age 42, while MAI of stand increased at early ages and then gradually decreased after culmination like MAIs of DBH and height. MAIs of basal area of dead trees at each measurement tended to increase until early age (18 years in this study), while it reached a peak and gradually decrease after that (21 years in this study). Correlation coefficient between DBH and height tended to decrease as both dominant and stand age and the difference between dominant and stand was not clearly shown over the measurement period. Correlation coefficients between DBH and crown width tended to decrease as the trees age and correlation coefficients of dominant were clearly shown smaller than that of stand. Correlation coefficients of height and crown width also was found to be similar to correlation coefficients between DBH and crown. Meanwhile correlation coefficient of height and crown width dropped more radically than coefficient of DBH and crown width as the trees age.

The Three-year Effect of Thinning Intensity on Biomass in Larix kaempferi and Pinus koraiensis Plantation

Vireak Chhorn,Yeongwan Seo,Daesung Lee,Jungkee Choi 강원대학교 산림과학연구소 2020 Journal of Forest Science Vol. No.

This study aimed to figure out and compare the increment of biomass by thinning intensity focused on the plantation of the two major coniferous species (Larix kaempferi and Pinus koraiensis) of South Korea. The inventory interval was three years under the effects of three types of thinning treatments; control (no thinning), light (20% thinning) and heavy (40% thinning). The results showed standing biomass increment of both species decreased as thinning intensity increased (heavy<light<control). Biomass increment of each tree compartment (roots, stem, branches and foliage) also followed the increment pattern of the total biomass. In contrast, the rate of biomass growth increased as increasing thinning intensity (heavy>light>control). Meanwhile, the lowest of on-site biomass changes occurred in the control plot, and the greatest was in the heavy thinning plot because thinning was involved with leaving the felling residual biomass (leaves, branches and roots) on the site. According to the results from this short-term study, unthinned stands is preferable for maximizing standing biomass as well as carbon sequestration. However long-term investigation should be considered in order to see more clear results.

Thinning Intensity for Large Diameter Trees in Korean White Pine Plantation of South Korea

Lee, Daesung,Seo, Yeongwan,Park, Jiyoung,Choi, Jungkee Institute of Forest Science 2017 Journal of Forest Science Vol.33 No.1

The purpose of this study is to analyze the effect of thinning intensity on the growth of large diameter trees in Korean white pine (Pinus koraiensis S. et Z.) plantation. Eight thinning plots were analyzed by categorizing into heavy thinning, light thinning, no thinning (control) according to thinning intensity. As a result, average DBH increased more in heavy thinning plots than in light thinning or unthinned plots. The number of large trees (DBH>25 cm) were obviously shown the most in heavy thinning plots. It is considered that heavy thinning is needed for the production of the large diameter trees.

Estimation and Validation of Taper Equations for Three Major Coniferous Species in Gangwon and North Gyeongsang Provinces of South Korea

Lee, Daesung,Seo, Yeongwan,Lee, Jungho,Choi, Jungkee Institute of Forest Science 2017 Journal of Forest Science Vol.33 No.4

This study was carried out to estimate the parameters of stem taper functions, to figure out the best taper model by species, and to compare with previous studies by species, targeting on the stemmed tree samples collected from the Korean red pine (Pinus densiflora), Korean white pine (Pinus koraiensis), and Japanese larch (Larix kaempferi ) stands in Gangwon and North Gyeongsang provinces of South Korea. The seven widely used models were applied in this study, and Muhairwe 1999 model for Korean red pine and Korean white pine and Kozak 2002 model for Japanese larch were evaluated as the best model for each species according to the fit statistics and the predicted stem form comparison. In addition, the predicted diameter was suitably fitted when comparing the previous studies, and the values were more appropriate following stem taper according to neiloid, paraboloid, and cone parts by species. Consequently, the estimation of this study was considered to represent the stem taper well. When comparing stem taper of three species, the diameter was largest in Korean white pine. Overall, the taper models of this study are judged to be useful for estimating stem form and volume computation of Korean red pine, Korean white pine, and Japanese larch.