• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.450-458
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• 1997

It is inadequate to compare operating costs between some logging machines with a low rate of utilization of them except the effect of operating time. The operating volume to maximize the utilization of the logging machines is different from each other, thus it is important to choose the proper logging machines and operating system according to the size of logging management. This study presents one of the methods to choose the economical optimum logging machines according to the operating volume to promote the economical efficiency of the machines. In order to go ahead with the Korean forestry mechanization plan, it should be considered which machine or operating system has the economical priority and if it can be suitable to the effect of wage increment.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.1
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• pp.46-54
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• 2021

This study compared and analyzed the effects of forest tending works on the vertical distribution of wildfire fuel loads on Pinus densiflora stands in Gyeongbuk province. The study sites were located in Youngju and Bonghwa in Pinus densiflora stands. A total of 10 sample trees were collected for the development of the crown fuel vertical distribution model. The 6th NFI (National Forest Inventory) selected a sample point that only extracted from managed and unmanaged stands of Pinus densiflora in the Gyeongbuk province. The fitness index (F.I.) of the two models developed was 0.984 to 0.989, with the estimated parameter showing statistical significance (P<0.05). A s a results, the vertical distribution of wildfire fuel loads range of unmanaged stands was from 1m to 11m with the largest distribution at point 5m at the tree height. On the other hand, the vertical distribution of wildfire fuel loads range of the managed stands was from 1m to 15m with the largest distribution at the point of 8m at the tree height. The canopy bulk density was 0.16kg/㎥ for the managed stands and 0.25kg/㎥ for the unmanaged stands, unmanaged stands were about 1.6 times more than managed stands. This result is expected to be available for simulation through the implementation of the 3D model as crown fuel was analyzed in three dimensions.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.339-350
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• 2009

This study was carried out to investigate distributional condition of rare plants and useful plant resources, and to verify distributional patterns of understory vegetation associated with the upper layer's vegetation structure. Total 59 families, 160 genera, 218 kinds of vascular plants were identified at the study site including 6 rare plants designated by Korea Forest Service (Lloydia triflora Bak., Trillium kamtschaticum Pall., Lilium distichum Nakai, Anemone koraiensis Nakai, Iris odaesanensis Y.N. Lee, Viola diamantica Nakai). Twenty three species of useful plant resources were also identified at the site; 8 of them showed clustered distributions and the others were prone to scatter. Actual vegetation of this study area consisted of one natural community dominated by Quercus mongolica Fisch. and three disturbed communities of Larix kaempferi (Lamb.) Carriere, Abies holophylla Max. and/or a herbaceous vegetation resulting from forest removal and strong wind of mountain top. This classification was strongly supported by cluster analysis based on the surveyed plot data. Distributional patterns of understory vegetation within forest stand were somewhat related to overstory vegetation structure, but showed a different tendency according to site condition, species composition, and competitive pressure among understory vegetation. Therefore, in order to protect the important understory components as forest genetic resources, forest treatments such as density control of overstory should be implanted based on understanding of impact on understory's dynamics and growing condition.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.36-42
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• 2001

Changes in breeding bird community and forest structure by thinning were investigated from April 1997 to August 1998 in 10ha ($400{\times}250m$) of temperate mixed hardwood forest in Mt. Gariwang which is located in National Forest, Pyoungchang, Kangwon Province, Korea. Bird community was surveyed by the territory mapping method and forest structure was done by analyzing the vertical structure of foliage, distribution of diameter at breast height (DBH) of trees and tree species composition. After the thinning, tree density, number of tree species and basal area were decreased from 195ea/ha, 18 species and 6.69 $m^2/ha$ into 100ea/ha, 13 species and 3.04 $m^2/ha$, respectively. Foliage coverages in upper and mid layer were decreased, but coverage in low layer was increased. Large trees (Over 40cm of DBH) were decreased. Number of breeding bird species and pairs were decreased from 14 species and 23 pairs into 8 species and 12 pairs after the thinning. Number of breeding pairs of Yellow-breasted bunting Emberiza elegans incresed. There were decrease in number of species in hole & bush-nesting and canopy & bush-foraging guild. The results suggested that the thinning affect the species composition of breeding bird community and the forest structure. Changes of habitat structure might influence in breeding bird's density, species diversity and habitat using pattern of breeding bird community.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.375-382
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• 2015

We classified the forest type and figured out the ecological characteristics for each of the types in order to provide the basic informations for being induced ecologically efficient forest practice plan by vegetation units in the natural forest of Songnisan. We established the 250 sample points and collected the vegetation data of vertical distribution for each sample. A variety of multivariate statistical methods were applied to classify the forest types. The species diversity index were analyzed to estimate the stability and maturity for forest vegetation in each the type. The types were divided from two to ten clusters by cluster analysis. The appropriate number of clusters was estimated five clusters by indicator species analysis. It was verified through the multiple discriminant analysis that the estimated number of clusters had been suitable. Based on the species composition for each the type, this study site was classified into five forest types: 1) Quercus serrata and 2) mixed mesophytic forest in the valley area, 3) Q. mongolica forest in the main ridge, 4) Pinus densiflora forest in the sub-ridge extending from the main, and 5) Q. variabilis-P. densiflora forest between the sub-ridge and valley. The species diversity index of the pine forest that had been a simple species composition was the lowest while that of the mixed mesophytic forest of which the composition had been diverse was the highest. As the forest vegetation was more varied, the index showed a tendency to increase.

• Journal of Korean Society of Forest Science
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• v.96 no.4
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• pp.477-482
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• 2007

Forest biomass became a topic because we have growing interest in global environmental issues and environment-friendly energy resources. This study was carried out to estimate the forest biomass and develop a program for biomass information management in Korea. The total forest biomass (million ton) were 521 for gross forest, 403 for productive forest and 201 for commercial forest in 2005. Also, the annual biomass production in forest was 20 million ton which was equivalent to 94,290 Gkcal of heating value and about 9 billion won of paraffin oil. The biomass growing rate (every 10year) increased from 4.95% in 1985 to 5.30% in 1995 but turn down 4.46% in 2005. The factors that the forest stock could be converted to the forest biomass have developed according to forest type. Therefore, it is impossible to estimate the exact biomass by tree species. In this reason, the demands of the development of the factors by tree species was raised. In addition, it is on time to develop an equation for estimation of biomass by species using dbh and height as independent factors.

• Journal of Korean Society of Forest Science
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• v.107 no.4
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• pp.336-343
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• 2018

This study was carried out to provide the technology of silvicultural practices and management for regeneration by sprouts in the oak forests distributed on the slope. A total of 1,451 stumps were examined for the following factors relative to the occurrence and growth of the sprouts: stump height & diameter; location & quantity and root collar diameter & height of arisen sprouts. The amount of sprouts deceased or increased as the stump diameter increased. However, it tended to increase with stump height. The difference in the stump height between direction of the upwards (DUS) and downward slopes (DDS) was occurred, because oak trees were felled lower based on direction of the upward for convenience of regeneration works on the slope. The number of sprouts was higher relatively in the stumps of DDS. The rate of arisen side and root sprouts was higher in the stumps of DDS and DUS, respectively. The stump height difference was found to affect the arisen part of sprouts. As a result of comparing the sprouts growth according to the arisen part, there was no difference in the stump of DUS, but the growth of side sprouts in the stump of DDS was higher than that of the root. In order to improve the quality of oak sprouts considering the distribution characteristics of the oak forests in South Korea, it is necessary to apply the silvicultural technique, making the cutting surface parallel with the slope to reduce the stump height difference, to suppress arising side sprouts.

• Journal of Korean Society of Forest Science
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• v.108 no.2
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• pp.189-199
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• 2019

The forest management paradigm has recently shifted from focusing on commercial production to focusing on ecosystem management. Accordingly, a natural seedling regeneration method that has a naturally high affinity has attracted much attention in recent years. The aim of this study was to determine the relationship among various environmental factors, lower stratum vegetation, and seedling regeneration in Pinus densiflora forests. The survey site comprised 50 sectors divided using the line transect method, and the survey data were divided into those from wet habitat (19 sites) and dry habitat (31 sites), depending on the soil humidity, and were analyzed separately to show the close relationship between soil humidity and natural seedling regeneration. As a result, the dry habitat exhibited high seedling density (157,419 trees/ha), with the main species being Quercus serrata, Zanthoxylum piperitum, Smilax china, and Pueraria lobata, while wet habitat exhibited low seedling density (57,895 trees/ha), with the main species being Stephanandra incisa, Castanea crenata, Lespedeza maximowiczii, Lysimachia barystachys, Aralia elata, and Styrax japonicus. The height and root-collar diameter under wet conditions exhibited faster growth than those under dry conditions. Height growth by the root-collar diameter in dry habitat increased faster than that in wet habitat. It was also confirmed that seedling regeneration in wet habitat exhibited a rapid growth pattern 5 years after germination. These results suggest that the seedlings begin to grow more rapidly after a period of suppression by competition with surrounding plants. Considering an ecosystem or ecological management approach, specific practices, such as bush control and vine clearing in wet habitats, should be more intensively conducted, especially at the beginning of the management operations.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.530-542
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• 2021

To establish the basic unit for the ecological management of the Larix kaempferiplantations in the Baekdudaegan protected area, we classified the vegetation types using TWINSPAN and DCA ordination analysis based on the vegetation information collected from 119 plots and analyzed their spatial arrangement status. Vegetation types were classified into seven types, including Quercus mongolica-Rhododendron schlippenbachii type, Q. mongolica-Lespedeza maximowiczii type, Cornus controversa-Morus australis type, Q. mongolica-Carpinus cordata type, Lindera erythrocarpa-Rosa multiflora type, Q. serrata-Zanthoxylum schinifolium type, and Q. serrata-Sasa borealis type and they have usually reflected differences in the floristic composition according to latitude, elevation, establishment period, operation history, characteristics of the surrounding stands, and degree of disturbance. Furthermore, using the Jaccard coefficient to comparethe floristic composition similarity between Larix kaempferiplantations and surrounding potential natural vegetation (Q. mongolica and Q. serrata forests), although some differences depended on vegetation types, it was 0.21 on average with Q. mongolica forest and 0.32 with Q. serrata forest, indicating that the floristic composition was still heterogeneous.

• Journal of Korean Society of Forest Science
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• v.82 no.4
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• pp.406-419
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• 1993

In spite of the economical and sivicultural importance, tending methods of natural broad leaf tree have not been established in Korea. In the present study, the structure of crown and biomass of Quercus variabilis were analyzed to obtain the basic information on pruning practice. There was not correlated between clear length of sample tree and tree height and D.B.H. The stratum with the largest leaf and branch weight was lower part of the stratum with the largest branch increment. The degree of contribution of branch to knotless trunk production (${\Delta}{\omega}_B(Z)/{\omega}_B(Z)$ and ${\omega}_L(Z)/{\omega}_B(Z)$) decreased from the upper part to the lower part. As an example of the application of the ecological data to pruning practice, the author attempted to estimate the effect of pruning with this experimental stand. Two methods of pruning were investigated. One is the removal of branches according to a definite external indication such as clear length rate of branch, and the other is the removal of barnches according to a definite height.