• Journal of Korean Society of Forest Science
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• v.94 no.3 s.160
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• pp.168-177
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• 2005

To provide the basic policy informations for environment-friendly and economical construction of green forest road, forest road density considering for the forest terrain and characteristics was computed. As results, designing the effective forest management and protection, standard forest road density as a social overhead capital (SOC) concept was computed to 8.57 m/ha. Considering as based facilities for forest management, we also optimal forest road density for preparing the sustainable forest management system was computed to 14.01 m/ha.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.115-121
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• 2016

This study was conducted to provide the basic policy information for establishing efficient forest-road networks. Synthetic forest-road networks that consist of main and spur roads and forest-road networks with only main road (hereafter called "main-road network") were planned for the five forest-road experimental districts of Korea Forest Service in this study. Road density of the synthetic forest-road networks was calculated and compared with the road density of the main-road networks. The results showed that the optimum road density of the synthetic forest-road networks was 10.1~15.9 m/ha, and the road density of the main-road networks was 8.4~12.4 m/ha. The construction cost of the synthetic forest-road networks was estimated about 1~8% lower than the main-road networks, while the road density was 20~30% greater than the main-road networks. As timber volume and hauling cost increased, the optimum road density of the synthetic forest-road networks increased, within which the road density of highstandard main road rapidly increased. On the other hand, the spur road density increased with slope gradient.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.648-655
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• 2012

This research is aimed at suggesting the reasonable guideline for managing tree density of a therapeutic forest to enhance the therapeutic efficiency. To obtain visually preferable tree density for 4 coniferous tree species; Pinus koraiensis, Chamaecyparis obtusa, Pinus densiflora, Larix kaempferi, the simulations of tree density according to the 3 diameter classes are used. 250 people participated in questionnaire and 239 people of them were analyzed. The tree density preferences of 4 tree species are as follows; Pinus koraiensis forest; tree density for trees with Diameter (DBH=D)<25 cm about 816/ha, tree density for trees with 25=D<40 about 400/ha and tree density for trees with 40=D about 277/ha. Chamaecyparis obtusa forest; tree density for trees with D<25 about 625/ha, tree density for trees with 25=D<40 about 625/ha and tree density for trees with 40=D about 400/ha. Pinus densiflora forest; tree density for trees with D<25 about 816/ha, tree density for trees with 25=D<40 about 625/ha and tree density for trees with 40=D about 400/ha. Larix kaempferi forest; tree density for trees with D<25 about 625/ha, tree density for trees with 25=D<40 about 625/ha and tree density for trees with 40=D about 277/ha.

• Journal of Forest and Environmental Science
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• v.38 no.3
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• pp.174-183
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• 2022

The study aims to examine population indices of mature trees in Jebel Elgarrie forest, Blue Nile State, Sudan. We used remote sensing techniques to stratify the forest into vegetation classes depending on tree density. We distributed 97 circular sample plots (0.1 ha) proportionally to the area of the vegetation classes. In each sample plot we identified, counted and recorded all mature trees (DBH ≥10 cm). We calculated frequency, density, abundance, richness, evenness and diversity for each species and we drew abundance rank curve of mature trees. We used One-Way ANOVA to test for differences (α=0.05) in mean density (No./ha) of mature trees between vegetation classes. Results revealed that the forest was conveniently sub-divided into high density (C1), medium density (C2), low density (C3) and bare farm land (C4) classes. We identified fifteen tree species that belong to 10 families and 14 genera. Combretaceae and Fabaceae were the common families while Anogeissus leiocarpa was the most frequently occurring species. While species diversity varied between vegetation classes, diversity of the forest as a whole is low. While mean density of mature trees in C1, C2, C3 and C4 it was 100, 74, 10, and 0, respectively, it was 54 for the whole forest indicating low stocking, Following One-Way ANOVA, multiple comparisons revealed significant differences in mean density of mature trees between C1 & C3 and C2 & C3. The study provided empirical results on population indices of mature tree species, which would be of importance for successful management and conservation of the forest.

• Proceedings of the KSRS Conference
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• v.1
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• pp.102-105
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• 2006

Forest canopy density is an essentially important for maintaining the diversify flora and fauna in the tropic. But, the natural and human disturbances have an influence over the inconsistency of forest canopy density. So, forest canopy density (FCD) has been threatened in the tropic since a decade. The objective of this study was to examine the dynamics change of the forest canopy density in tropical forest Chitwan, Nepal combine with field survey and remote sensing data. The field survey data of 2001 such as canopy cover percentage, dbh so on and some human disturbances were used. Similarly, Landsat TM 1988 and ETM+ 2001 have also used to predict the dynamic changes of the FCD over the period. Moreover, nonparametric Kruskal- Wallis test has performed for the validation of the results. Data analysis revealed that very few factors i.e. the number of trees, path, and fire had realized statistically significance at P=<0.05. Therefore we concluded that detail analysis could be needed incorporate with additional socioeconomic, climatic, biophysical and institutional factors for the better understanding of the forest canopy dynamic in particular location.

• Journal of Environmental Health Sciences
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• v.44 no.3
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• pp.205-216
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• 2018

Objectives: Scientific verification for health effects has been constantly demanded through the forest healing factors. In this study, phytoncide concentration which is one of the forest healing factors, was investigated according to stand density, season and visiting time, and analyzed correlation with micrometeorology factors. Methods: Total volatile organic compounds (TVOCs) and Natural volatile organic compounds (NVOCs) were collected using a measuring instrument which is connected to an air pump with the Tenax TA tube. The 32NVOCs were selected through the detailed criteria of adequacy assessment for recreational forest. The statistical analysis (correlation and stepwise regression analysis) was conducted between phytoncide concentration and micrometeorology factors. Results: NVOCs concentration linearly increased according to stand density. The high level showed in the summer (p<0.05), and there is no significant difference according to visiting hours of the Healing forest. NVOCs is a negative correlation with solar radiation, PAR and wind direction, and a positive correlation with relative humidity and temperature (p<0.01). NVOCs increased following the increase of humidity and temperature ($R^2=0.55$). Conclusions: Phytoncide linearly increased according to stand density, and showed the correlation significantly with microclimate factors. In future, these results will be utilized as a basic material to promote the generation of phytoncide, which positively influences human health promotion and manage the forest welfare space.

• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.175-181
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• 2014

This study was conducted to evaluate stand density-specific and generalized allometric equations, and biomass expansion factors (BEFs) for two stand densities (high density of 47-year-old: $667tree{\cdot}ha^{-1}$; low density of 49-year-old: $267tree{\cdot}ha^{-1}$) of Cryptomeria japonica plantations in Namhae-gun, located in the southern Korea. Biomass in each tree component, i.e. foliage, branch, and stem, was quantified by destructive tree harvesting. Allometric regression equations of each tree component were significant (P<0.05) with diameter at breast height (DBH) accounting for 80-96% of the variation except for branch biomass in high density or foliage and cone biomass in low density. Generalized allometric equations can be used to estimate the biomass of C. japonica plantations because the slopes of allometric equations were not significantly different by the stand density. The biomass expansion factors (BEFs) were significantly lower in the high stand density (1.33) than in the low stand density (1.50). The results indicate that BEFs were affected by different stand density, while allometric equations were little related to the stand density.

• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.202-210
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• 2020

This study investigated the optimal levels of stand density control considering the stability of Larix kaempferi stands. A stand density management diagram was developed from 259 sample plots. Based on these data, we determined an optimal level of the stand density control by identifying the relationship between the relative yield index (Ry) and height-to-diameter ratio. The estimated r-square (R²) of the stand density management diagram is 0.600. The analysis of the relationship between Ry and the slender tree incidence showed that when the stand density exceeded a certain threshold and the ratio of slender trees rapidly increased. The critical value of Ry was 0.63. The results of this study are expected to contribute to the establishment of stand management strategies that can reduce damage from natural causes, such as wind and snow, and to develop stand practice systems for the improved productivity of commercial forests.

• Journal of Forest and Environmental Science
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• v.33 no.4
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• pp.305-314
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• 2017

This study aimed to predict changes in forest area using a probability density function, in order to promote effective forest management in the area north of the civilian control line (known as the Minbuk area) in Korea. Time series analysis (2010 and 2016) of forest area using land cover maps and accessibility expressed by distance covariates (distance from buildings, roads, and civilian control line) was applied to a probability density function. In order to estimate the probability density function, mean and variance were calculated using three methods: area weight (AW), area rate weight (ARW), and sample area change rate weight (SRW). Forest area increases in regions with lower accessibility (i.e., greater distance) from buildings and roads, but no relationship with accessibility from the civilian control line was found. Estimation of forest area change using different distance covariates shows that SRW using distance from buildings provides the most accurate estimation, with around 0.98-fold difference from actual forest area change, and performs well in a Chi-Square test. Furthermore, estimation of forest area until 2028 using SRW and distance from buildings most closely replicates patterns of actual forest area changes, suggesting that estimation of future change could be possible using this method. The method allows investigation of the current status of land cover in the Minbuk area, as well as predictions of future changes in forest area that could be utilized in forest management planning and policymaking in the northern area.

• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.261-266
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• 2015

This study was conducted to examine the effect of tree density of Pinus koraiensis forest on the thermal comfort and the physiological response of human body in summer season. As the indicators of thermal comfort were used the predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD), while the heart rate variability was used for the physiological indicator of subjects. The subjects were 15 physically healthy men and women in their 20s ($23.7{\pm}1.7$ years old). The subjects sat in each site to measure HRV for 5 minutes and the thermal comfort of each site was measured. As a results, it was proven by PMV and PPD that the Pinus koraiensis forest with 120% tree density was thermally more comfortable than the Pinus koraiensis forest with 80% tree density. In case of the subjects' physiological response, the Pinus koraiensis forest with 120% tree density showed significantly higher HF of HRV than the Pinus koraiensis forest with 80% tree density and significantly lower LF/HF. Therefore, the findings of this study scientifically proved that the Pinus koraiensis forest with 120% tree density is thermally more comfortable and physiologically more relaxing than the Pinus koraiensis forest with 80% tree density.