• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.567-582
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• 2022

Chainsaw use for motor-manual timber harvesting in South Korea is associated with worker safety issues. However, forestry operations such as timber harvesting have already been mechanized to reduce hazards to workers and increase productivity. This study analyzed the productivities and costs of felling and processing, felling and processing using an excavator-based stroke harvester for Pinus rigida and Quercus mongolica stands. To efficiently operate the stroke harvester, we developed a regression equation to estimate the productivities of felling and processing, felling, and processing operations,and we conducted sensitivity analysis of the operation costs using DBH and machine utilization. The felling and processing productivity was 6.53 and 4.02 m³/SMH for P. rigida a nd Q. mongolica, respectively, and the cost was 17,983 and 29,210 won/m³, respectively. The felling productivity for P. rigida a nd Q. mongolica wa s 40.9 and 23.0 m³/SMH, respectively, and the cost was 2,667 and 4,743 won/m³, respectively. The processing productivity for P. rigida and Q. mongolica was 8.25 and 7.75 m³/SMH, respectively, and the cost was 15,296 and 16,283 won/m³, respectively. In the developed regression equation, the DBH, traveling distance, and number of cuttings were found to be important factors (p<0.05). Therefore, it is necessary to construct a DB considering the various conditions and species associated with harvester operations, and further research is needed to increase the accuracy of predicting operation productivity and costs.

• Journal of Korean Society of Forest Science
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• v.96 no.6
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• pp.742-749
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• 2007

The objective of this study was to develop thinning effect analysis model (TEAM) using individual-tree distance-independent growth model of Pinus koraiensis Stands. The TEAM was designed to analyze thinning effects associated with such thinning prescriptions as the number, timing, intensity, and method of thinnings. To testing TEAM application, stand growth effects were compared with seven scenarios according to thinning prescription plan. In the results, it was possible to estimate the number of trees, height, volume with diameter (DBH) class of individual trees, and average diameter growth, height growth, the number of trees and volume growth per ha of stands. The result of sensitivity analysis on one Pinus koraiensis stand, it was not sure to expect the much more volume at the rotation age by stand density control applying thinning prescription. In the case of thinning, total yield volume has much more $40{\sim}75m^3$ per ha, within 5 cm in average diameter growth and within 1 m in average height growth than thats of non-thinning over increasing stand age. TEAM, as decision making support system, can be used for selecting the thinning prescription trial and determining one of some thinning prescription plan in different site specific stand environments.

• Korean Journal of Environment and Ecology
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• v.37 no.5
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• pp.347-366
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• 2023

In the present study, the vegetation was classified using the phytosociological method and canonical-correlation analysis (CCA) was implemented to analyze correlation between community structure and environmental factors in the natural habitats of forest byproducts, especially medicinal plants, such as Cudrania tricuspidata, Sorbus commixta, and Hovenia dulcis, in 2021-2022 to provide primary ecological data to establish environmental conditions for wild vegetable cultivation. A total of 11 plots in five regions, 8 plots in three regions, and 17 plots in 5 regions were selected for the natural habitats of C. tricuspidata in southern Korea, S. commixta in high mountains, and H. dulcis in valleys of central Korea, respectively. The importance value in each community was respectively analyzed as follows, in C. tricuspidata community, the importance value of C. tricuspidata (61.10) was the highest, followed by Celtis sinensis, Pinus thunbergii, Neolitsea aciculata, Styrax japonica, Carpinus coreana, Quercus serrata, and Q. acutissima. In Sorbus commixta community, Q. mongolica (57.21) was the highest, followed by, S. commixta (42.58), Betula ermani, Tilia amurensis, A. pseudosieboldianum, A. tschonoskii var. rubripes, Cornus controversa, Magnolia sieboldii, and Taxus cuspidata. In H. dulcis community, H. dulcis (64.58) was the highest, followed by Zelkova serrata, Cornus controversa, A. mono, Q. serrata, C. cordata, and Juglans mandshurica. As the result of the analysis on DBH of the major species having the high importance value, in C. tricuspidata community, C. tricuspidata, C. sinensis, Neolitsea aciculata, and C. coreana show the density of normal distribution, so the dominant status of these species is likely to continue. In S. commixta community, S. commixta show the density of reverse J-shaped curve, so the dominant status of these species is likely to be stable, and Q. mongolica, B. ermani and T. amurensis, show the density of normal distribution, so the dominant status of these species is likely to continue. In H. dulcis community, C. cordata, and J. mandshurica show the density of reverse J-shaped curve, so the dominant status of these species is likely to be stable, and H. dulcis, Z. serrata, C. controversa and A. mono had a formality distribution, suggesting a continuous domination of these species over the other species for the time being. The results of CCA ordination analysis using 11 environmental factors and 30 communities of three taxa classified by TWINSPAN analysis revealed that the altitude showed the strongest correlation with the vegetation. C. tricuspidata community was distributed on the moderate and gentle northeastern slope at low altitude with the highest pH, C.E.C, Ca²⁺, and Mg² and various P₂O₅, whereas S. commixta community was distributed on the steep slope at high altitude with the highest O.M and T-N and lower P₂O₅, Ca²⁺, Mg²⁺, C.E.C and pH, which is the opposite tendency of the environment of C. tricuspidata community. H. dulcis community was distributed on the gentle northern slope at lower altitude with an average pH, O.M, T-N, Ca²⁺, Mg²⁺, and C.E.C, except higher P₂O₅.

• Korean Journal of Environment and Ecology
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• v.22 no.4
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• pp.396-408
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• 2008

Gwangtan-myeon, Paju-si, Gyeonggi-do was classified as a 4 grade age-class deciduous tree forest, however as a result of vegetation survey, this site was found to consist of natural forest with deciduous trees, thus causing difficulty in judging which age class it belongs to. Subsequently, the necessity of drawing up a detailed stock map plan was raised. For this reason, this research was designed to propose a mapping method for a detailed stock map plan based on a detailed survey on actual vegetation, vegetation structure, and analysis data on tree rings. The detailed analysis of actual vegetation pattern showed that there exist 22 patterns of vegetation, in which the natural forest has 11 patterns, such as Quercus mongolica forest and Q. variabilis forest, etc. while the artificial forest was found to have 6 patterns including Castanea crenata, etc. In order to verify their age-class, this research measured a tree age by collecting 42 quadrats and 89 specimen tree cores on the basis of a detailed actual vegetation map; as a result, an artificial forest and oak trees with small diameters located at low-lying areas, was categorized as 2-grade age class(covering 29.8%), and other areas were judged to be available for land use as 3-grade age-class(covering 57.6%) while the areas judged to be 4-or-more grade age-class (covering 8.8%) was impossible for land use because they are located on a steep slope ridge line on a boundary. In case a proposed site for a small-scale development is judged as a natural forest with deciduous trees as mentioned above, it is necessary that a detailed stock map plan should be drawn up through a detailed investigation into actual vegetation and analysis of plant gathering structure & specimen trees. A detailed stock map plan includes the data that makes it possible to comprehensively judge natural property, scarcity, and diversity of vegetation; thus, it is considered that a detailed stock map plan will be useful in judging the development propriety of a small-scale site.

• Journal of Korean Society of Forest Science
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• v.77 no.2
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• pp.166-177
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• 1988

To investigate the structure of the plant community of the Naejang Temple District in Mt. Naejang National Park, 22 plots were set up by the vegetation physiognomy and vegetation analysis by four kinds of ordination techniques(PO, PCA, RA and DCA) was carried out. Pure and mixed forest community of Quercus variabilis and Q. mongolica were major forest communities and each of them covered 31.27 and 20.77%, respectively. The degree of human disturbance of vegetation 9, 8, 7 and 6 area covered 30.9, 67.0, 0 and 0.02%, respectively. According to stand dynamic analysis by DBH class distribution, the present Pinus densiflora and Quercus communities may be succeeded to Carpinus laxiflora communities. DCA was the most effective method of this study. DCA ordination showed that successional trends of tree species seem to be from P. densiflora through Q. variabilis, Q. aliena, Sorbus alnifolia, Platycarya strobilacea to Carpinus laxiflora, Fraxinus rhynchophylla, Zelkova serrata, Cornus controversa in the tree layer, and from Rhododendron mucronulatum, Rh. schlippenbachii, Lespedeza cyrtobotrya, Rhus trichocarpa through Styrax japonica, Daphniphyllum macropodum, Sapium japonicum to Euonymus oxyphyllum, E. sieboldiana, Lindera erythrocarpa in the subtree layer.

• Korean Journal of Environment and Ecology
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• v.16 no.4
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• pp.457-464
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• 2003

A valley forest in Sangbuun area at Jirisan National Park was studied to investigate forest structure in relation to altitude and part of the slope. Forty-eight quadrats were set up in the valley forest along altitude of 726m to 1,090m and part of the slope, and vegetation analysis for the woody species in the tree and subtree layers were carried out. With increasing elevation belt, mean DBH, height and basal area of the trees in the tree layer increased while their density decreased. This trends may be caused by the disturbance which was relatively severe in the low elevation area. As elevation increased, the importance percentages of Fraxinus rhynchophylla, Quercus variabilis and Quercus mongolica increased while those of Styyax japonicus, Carpinus laxiflora and Pinus densiflora decreased. The importance percentages of Quercus variabilis and Pinus densiflora increased as going from lower part to upper part of the slope. However, the opposite trend was found for the importance percentages of Acer mono and Corlus heterophylla var. thunbergii. Number of species and species diversity decreased as increasing elevation and going from lower part to upper part of the slope. According to importance percentage and cluster analysis, the valley forest was classified into three forest communities of Quercus serrata-broad-leaved tree species community in lower part of the slope at low elevation belt, middle elevation belt and middle and upper parts of the slope at high elevation belt, Pinus dnsiflora-Quercus serrata community in middle and upper parts at low elevation belt, and Quercus mongolica-broad-leaved tree species community in lower part of the slope at high elevation belt and top area.

• Korean Journal of Environment and Ecology
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• v.35 no.6
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• pp.632-643
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• 2021

The objective of this study was to examine vegetation community structure and distribution of Fraxinus chiisanensis in Mt.Minjuji of Chungcheongbuk-do by setting up and surveying 8 plots (400 m² each). Mean Importance Value (MIV) of Fraxinus chiisanensis in 8 plots was 35.19% in average (ranging from 26.07~42.74%). Since it is the dominant species in all plots, it is expected to maintain the present vegetation structure. The analysis of the DBH (diameter at breast height) showed that the diameter of Fraxinus chiisanensis in Mt.Minjuji ranges from 2 to 43cm. The majority of Fraxinus chiisanensis is expected to maintain current state unless disturbance or rapid environmental change occurs. The Species Diversity (H') was 0.8498~1.0261, Evenness (J') was 0.8160~0.9256, Dominance Index (D) was 0.0789~0.1840, Maximum Diversity (H'max) was 1.0414~1.2041. The analysis of annual ring and radial growth showed that the average age of Fraxinus chiisanensis in Mt.Minjuji was 29.1years(ranging from 22~58years). The average annual radial growth of Fraxinus chiisanensis was the highest in community G with 5.84mm and the lowest in community B with 2.80mm. The similarity index analysis revealed that the similarity index between community B and E, C and F, H was the highest with 69.0%, and the similarity index between community E and F was the lowest with 29.6%. Both the area of Fraxinus chiisanensis community of Mt.Minjuji and its population size are very small. Therefore, this area needs to be designated as Forest Genetic Resource Reserve.

• Journal of Korean Society of Forest Science
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• v.112 no.4
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• pp.405-416
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• 2023

In this study, the sustainability of Abies nephrolepis in the presence of Tripterygium regelii was analyzed. To accomplish this, a field survey of140 stands was conducted. Based on the presence or absence of T. regelii, as well as the layer in which it was present (where appropriate), the type of T. regelii presence wasclassified as follows: TP type, indicating the presence of T. regelii in the tree and sub-tree layers; SP type, indicating its presence in the shrub layer; and A type, indicatingits absence from all layers. The indicator species analysis revealed T. regelii to be an indicator species of the TP type and SP type. The MRPP test was used to examine the differences among the types. Moreover, the seedling and DBH class analysis indicated there to be a difficulty in terms of the status competition, as the number of young trees generated by A. nephrolepis was the lowest in the TP type. The findings of this study enhanced our understanding of the vegetation structure of A. nephrolepis, thereby contributing to efforts concerningits conservation and management.

• Journal of Korean Society of Forest Science
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• v.113 no.2
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• pp.187-197
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• 2024

In this study, we aimed to identify the factors influencing post-fire mortality in Korean red pine (Pinus densiflora) using Cox's proportional hazards model and analyze the impact of these factors. We monitored the mortality rate of fire-damaged pine trees for seven years after a forest fire. Our survival analysis revealed that the risk of mortality increased with higher values of the delta normalized difference vegetation index (dNDVI), delat normalized burn ratio (dNBR), bark scorch index (BSI), bark scorch height (BSH) and slope. Conversely, the risk of mortality decreased with higher elevation, greater diameter at breast height (DBH), and higher value of delta moisture stress index (dMSI) (p < 0.01). Verification of the proportional hazards assumption for each variable showed that all factors, except slope aspect, were suitable for the model and significantly influenced fire occurrence. Among the variables, BSI caused the greatest change in the survival curves (p < 0.0001). The environmental change factors determined through remote sensing also significantly influenced the survival rates (p < 0.0001). These results will be useful in establishing restoration plans considering the potential mortality risk of Korean red pine after a forest fire.

• Journal of Korean Society of Forest Science
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• v.106 no.3
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• pp.275-287
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• 2017

The purpose of this study was to analyze forest vegetation type classification and relationships between the type and environment factor in Mt. Dutasan. Data were collected by total of forty six plots using Z-M phytosociological method from June to October, 2016, and analyzed by vegetation classification, canopy layer structure and relationships between vegetation unit and environment factor using coincidence methods. As a result of vegetation type classification, Quercus mongolica community group was classified at a top level of vegetation hierarchy that was classified into Rhododendron schlippenbachii community and Betula costata community. R. schlippenbachii community was divided into Lychnis cognata group and R. schlippenbachii typical group. L. cognata group was subdivided into Veratrum oxysepalum subgroup and L. cognata typical subgroup. B. costata community was divided into Fraxinus mandshurica group and Betula schmidtii group. F. mandshurica group was subdivided into Weigela subsessilis subgroup and Cimicifuga heracleifolia subgroup. Therefore the forest vegetation was composed of six vegetation units with two kinds of bisected species groups and fourteen species groups. As the result of an analysis of canopy layer structure, there were two kinds of structures with monotonous structures V. oxysepalum subgroup (vegetation units 1), L. cognata typical subgroup (vegetation units 2), W. subsessilis subgroup (vegetation units 4) and complicated structures R. schlippenbachii typical group (vegetation units 3), C. heracleifolia subgroup (vegetation units 5), Betula schmidtii group (vegetation units 6). The vertical layer structure of vegetation unit 5 was the most developed and vegetation unit 6 had the lowest coverage of herb layer. According to the correlation between vegetation unit and environmental factor, R. schlippenbachii community (vegetation units 1~3) and B. costata community (vegetation units 4~6) were classified based on 1,100 m of altitude, middle slope, twenty of slope degree, twenty percents of bare rock and thirty centimeters of DBH in tree layer. R. schlippenbachii community (vegetation units 1~3) showed positive correlation with altitude, topography and B. costata community (vegetation units 4~6) showed negative correlation tendency with them.