• Korean Journal of Environment and Ecology
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• v.21 no.6
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• pp.554-558
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• 2007

Current biomass stock of forest has been calculated by using biomass expansion factors (BEFs) that convert timber volumes to dry weight and stem density. The objective of this study was to estimate stem density values and to develop BEFs that are dependent on tree age classes for Quercus acuta stands in Jeonnam Wando-gun. Sample trees on the three different age classes were harvested to obtain each components biomass with stem analysis. Stem density values as tree age classes were ranged from 0.557 to 0.636. Aboveground BEFs were ranged from 1.168 to 1.324. BEFs were increased with increasing age classes. There was a significant difference between BEFs and stem density values with tree age classes. These results suggest that the reliability of the national carbon stock inventory could be improved by applying age classes BEFs, which are formulated on the basis of representative for Quercus acuta.

• Journal of Korean Society of Forest Science
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• v.96 no.2
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• pp.138-144
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• 2007

This study was undertaken to compare the biomass of Abies koreana growing at two sites. A $10{\times}10m$ plot was established in each site of a natural stand in Mt. Jiri and a plantation in Gyeongsan nursery. Five trees of A. koreana were randomly selected in each site. The following traits were investigated from each tree : height, basal diameter, age, weight of stem, branches, and needles as above-ground traits and weight of total roots, horizontal roots, and vertical roots as below-ground traits. In Gyeongsan nursery, age of sample trees was negatively correlated with both height and weight of total stem, while height was highly correlated with weight of horizontal roots. There was high correlation between the basal diameter and weight of total stem, and between the basal diameter and weight of roots. In Mt. Jiri stand, most of the above-ground traits except age were significantly correlated with the below-ground traits. The linear regression equation between the cross section area of base (X) and the weight of total stem (Y) in Gyeongsan nursery was Y=12.66X-12.92, and correlation was significant ($R^2=0.89$). The linear regression equation between the cross section area of base(X) and the weight of total branches (Y) in Mt. Jiri stand was Y=25.51X+6.00, and correlation was highly significant ($R^2=1.0$).

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.543-549
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• 2013

This study was conducted to evaluate age-specific and generalized allometric equations and biomass expansion factors (BEFs) for each tree component across three age-sequence stands (35-year-old, 51-year-old, 62-year-old) of black pine (Pinus thunbergii Parl.) in Jinju, located in the western part of Gyeongnam province, Korea. Biomass in each tree component, i.e. foliage, branch, and stem, was quantified by destructive tree harvesting. Allometric regression equations were significant (P<0.05) with diameter at breast height (DBH) or combination of DBH and height ($DBH^2H$) accounting for 55-98% of the variation (as indicated by coefficients of determination, $R^2$) in aboveground biomass except for foliage biomass of the 62-year-old stand. Generalized allometric equations can be used to estimate the biomass of black pine stands because the slopes of age-specific equations over 35-year-old stands were not significantly different by the age-sequence. The stem density and biomass expansion factor (BEFs) were not significantly different (P>0.05) from different stand ages and ranged from 0.45 to $0.51gcm^{-3}$, and from 1.32 to 1.38, respectively. The results indicate that allometric equations, stem density and aboveground BEFs in the matured black pine over 35-year-old are little influenced by different stand ages.

• Journal of Environmental Science International
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• v.13 no.3
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• pp.181-187
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• 2004

In case an average accumulation of the investigated area is 200$m^{3}$/ha with cutting age of 80 years applied, annual workload will be 77ha and require 5 teams; each team consisting of 5 persons, enabling stabled supply of lumbers of 15,500$m^{3}$ every year. If one cutover is less than 2ha with cutting age of 80 years applied, it's possible to protect the peculiar ecology and secure stabled labor, workload and lumbering. It may become model forest out of tropical forest management which is controversial all over the world. Of course this presupposes construction of access roads.

• Journal of Environmental Science International
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• v.31 no.1
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• pp.51-59
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• 2022

This study investigated the effects of participation in a forest therapy program on ego-resiliency and interpersonal relationships to strengthen the independent capabilities of children requiring protection. The participants were divided into two groups: the experimental group (n=87; age, 16.40±1.90 years) and control group (n=90; age, 16.97±1.39 years). The study was conducted from July to August 2020. The experimental group participated in a forest therapy program operated by the National Center for Forest Therapy, Yeongju, for 2 nights and 3 days, whereas the control group lived routine life. The participants' ego-resiliency and interpersonal relationships were tested at the beginning and end of the forest therapy program. In the experimental group, ego-resiliency was improved and interpersonal relationships were significantly altered. Therefore, forest therapy programs may serve as effective interventions that can positively affect the social adaptation and growth of protected children into healthy adults.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.225-230
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• 2009

Using dynamic programming, which is one of operations research techniques, the best pathway was chosen to maximize the total harvest volume for a Korean white pine (Pinus koraiensis) stand. This study was carried out in an age class III at Chuncheon National Forest, Gangwon province. That stand was assumed to apply 3 different thinning intensities of none, 30% and 50% thinnings. These thinning pathways are planned to implement two times, of thinning at 35 age and 55 age. The final cutting (rotation age) is assumed to carry out in 70 years. A growth function for Korean white pine stand was developed with forest inventory data, the volume was calculated with this growth function. As a result, the best thinning pathway for this Korean white pine stand using dynamic programming is to implement 30% at the first thinning and 50%at the second thinning.

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.417-422
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• 2011

In general, forest tending work contributes to preventing landslides by enhancing forest health. In order to quantify beneficial effects of forest tending, landslide occurrences in forest tending area and those in non-forest tending area were compared and analyzed. The landslide had been hit hard in Inje and Pyeongchang county, Gangwon province, following Typhoon 'Bilis' on July 15, 2006. Data on forest tending of Pinus koraiensis and Larix kaempferi stands were acquired from the Inje National Forest Station, North regional forest service. The rate of landslide occurrence was increased sharply just after forest tending work and was decreased as time goes by. The analysis also found that the change in landslide frequency was slight by age class in the non-forest tending area, while it decreased as age class increased in the forest tending area.

• Journal of Forest and Environmental Science
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• v.35 no.3
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• pp.150-158
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• 2019

Exotic conifer trees have been extensively planted in southern China because of their high apparent growth and yield. These fast-growing plantations are expected to persist as a considerable potential for temporary and long-term carbon sink to offset greenhouse gas emissions. However, information on the carbon storage across different age ranges in exotic pine plantations is often lacking. We first estimated the ecosystem carbon storage across different age ranges of exotic pine plantations in China by quantifying above- and below-ground ecosystem carbon pools. The carbon storage of each tree component of exotic pine (Pinus elliottii) increased significantly with increasing age in Duchang and Yiyang areas. The stem carbon storage except <10 years in Ji'an areas was the largest component among all other components, which accounts for about 50% of the total carbon storage followed by roots (~28%), branches (~18%), and foliage (~9%). The mean total tree carbon storage of slash pine plantations for <10, 10-20 and 20-30 years across three study areas was 3.69, 13.91 and $20.57Mg\;ha^{-1}$, respectively. The carbon stocks in understory and forest floor were age-independent. Total tree and soil were two dominant carbon pools in slash pine plantations at all age sequences. The carbon contribution of aboveground ecosystem increased with increasing age, while that of belowground ecosystem declined. The mean total ecosystem carbon storage of slash pine plantations for <10, 10-20 and 20-30 years across China was 30.26, 98.66 and $98.89Mg\;ha^{-1}$, respectively. Although subtropical climate in China was suitable for slash pine growth, the mean total carbon stocks in slash pine plantations at all age sequences from China were lower than that values reported in American slash pine plantations.

• Journal of Korean Society of Forest Science
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• v.105 no.3
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• pp.360-365
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• 2016

The purpose of this study is to provide the basic information for the early enforcement and extension of the improvement project of management scale of private forest land by understanding the characteristics of forest owners, who have an influence on the participation of the project as one of the private forest management vitalization plans. To achieve this goal, a questionnaire survey targeting 373 forest owners was conducted and analyzed by Binary-Logistic Regression. The variables for binary-logistic regression included gender, age, academic ability, occupation, income, residence, purpose of forest ownership, and status of cooperative membership. As a result of the analysis, 267 forest owners (71.6%) of total 373 forest owners have the intention to participate in the scaling project for private forest management. The rest of forest owners (106 forest owners, 28.4%) would not be willing to participate in the project. As a result of binary-logistic regression, the most important variables, which have an impact on the participation of private forest management scale improvement project, are age, job and forest own purpose.

• Journal of Forest and Environmental Science
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• v.32 no.4
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• pp.377-383
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• 2016

We obtained a total of 36 GPS coordinates of the seven bat species of Rhinolophus ferrumequinum, Myotis ikonnikovi, M. nattereri, M. petax, Murina ussuriensis, Plecotus auritus, and Pipistrellus abramus. Characteristics of forests (forest type, age class, DBH class and crown density), terrain (aspect, slope and distance from mountain stream) and disturbance factors (distance from human residential areas and distance from cultivated areas) that bats have used as their habitats were revealed from the GIS analysis based on GPS coordinates of the 36 positions that bats were found. The bats-preferred forest type is broad-leaf forests (43%) with the trees of the 2th (31%) and 5th (31%) age class, the trees of sapling (36%) and large DBH class (31%), and sparse crown density (67%). Bats prefer the slop direction of the east (39%), the gradient below $15^{\circ}$ (61%), the ranges within 200 m from the mountain streams (92%), the ranges within 200 m near roads (89%), the ranges of 200-400 m from human residential areas (28%), and the ranges within 200 m from cultivated areas (36%).