• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.4
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• pp.67-75
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• 2006

This study compared with the object of designation and the management practices for Protection Forests between Korea and Japan to establish the management and development directions of Korea's Protection Forest. 1. Water conservation forest from total areas of Protection Forests occupied 90.6 % in Korea and 68.4 % in Japan, respectively. The water conservation forest was the most important function among the Protection Forest's functions in both countries. 2. The 10 million ha of Protection Forest in Japan increased for last 100 years. The 100 thousand ha per year was designated as Protection Forest. In contrast, The 655,535 ha of Protection Forest in Korea decreased for last 42 years with decreasing of 15,000 ha per year. 3. In Japan, Protection Forest can be managed by forest silvicultural practices such as forest harvest, thinning, and pruning to recover and improve the Protection Forest's functions. 4. In case of Korea, it is necessary to a mid- or long-term counter plan to increase the area of Protection Forest by the government, and needs to the recovery and improvement of Protection Forest's functions.

• Journal of Korean Society of Forest Science
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• v.96 no.6
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• pp.639-643
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• 2007

The use of forest biomass resources produced by forest tending and residual forest biomass that was not gathered on commercial thinning or cutting area was estimated to be come into the spotlight as bioenergy sources in these days of new high oil price. With considering these problems, This study was investigated about possibility with biomass calculation and convertibility to fossil fuel in these area. Total forest tending area in the year 2005 was 294, 115 ha and the yield gathered from these area was $143,747m^3$. It is equivalent to biomass of 115,000 ton and caloric value of 533,199Gcal. However, the potential and additional yield that is residual in forest stands was 2,483,000 ton. It is equivalent to 11,133 billion won of oil which is 20 times of the actual yield produced by forest tending. Therefore, these amount of biomass has a substitution effect of the fossil fuel. Moreover, the residual biomass that is not gathered at commercial thinning and cutting area was 475,000 ton. It is equivalent to 2,206,235 Gcal of heating value and about 2,211 billion won of oil. This potential amount could be a new energy source to be a substitution effect of fossil fuel. It is time to be interested in the forest biomass as a renewable and environment-friendly resource and its substitution effect of fossil fuel.

• Journal of Korean Society of Forest Science
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• v.97 no.2
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• pp.144-151
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• 2008

Using 8 isozyme polymorphic loci as gene markers, we studied the spatial distribution of genotypes in a naturally regenerated uneven-aged Eastern Siberian Fir (Abies nephrolepis Max.) stand (1ha, $100{\times}100m$) on Mt. Ohdae in northeastern South Korea. Gregorius' distograms and Moran's I correlograms revealed no evidence of significant genetic structure at three spatial classes of 5 m, 10 m, and 20 m. Extensive gene flow, due to the long distance dispersal of pollen and seeds in A. nephrolepis, may account for the lack of fine-scale spatial structure. Alternatives would be overlapping seed shadows caused by high densities of A. nephrolepis adult trees (160 trees/ha) and/or intraspecific competition resulting in extensive thinning within maternal half-sib groups.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.645-653
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• 2010

This study carried out the recognition of appropriate forest managements and directions in Jirisan National Park. For this purpose, we undertook interview survey about the recognition of forest management in Jirisan National Park from ecological and forest research fields' experts. From the statistical analysis results, it was founded that the difference among respondents' types was detected about recognition of forest management in National park. However, all the respondent types recognized that the forest management in National park is essential. So the forest management in national park by forest experts and relevant institutions are revealed needed.

• Journal of Korean Society of Forest Science
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• v.105 no.3
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• pp.342-350
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• 2016

This study aims to make the stand density management diagram which is very useful for establishing systematic management plan and obtaining management goal in Pinus densiflora forest. To estimate 5 models mainly composed of stand density management diagram, we used total of 1,886 sample plots having more than 75% of the total basal area of the pine trees in each stand. To test the goodness of fit, $X^2$ was computed with a significance level of 5%, and the acceptable error range as 20%. Also standard deviation of the model was $34.59m^3{\cdot}ha^{-1}$, minimum acceptable error range was 16.59% and coefficient of variation was 22.11%. If we use the stand density management diagram, it would be useful to establish the timber yield and thinning plan understanding the pathway of stand density management.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.580-589
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• 2015

The artificially grown forests of larch, planted in accordance with the nationwide afforestation policy in the 1970s, are located inside national parks. This study intended to induce a forestation system by which the forests develop into an ecologically healthy and broadleaved ecosystem with broad species diversity. For this, the aspects of natural regeneration of broadleaves from 2010 to 2013 after thinning by density (30%, 50%, and 70%) in 2009 were surveyed using the larch forest in the Woljeong Temple region inside Odaesan National Park. There were no trees that were larger than 2 cm in in diameter at breast height among the trees recently introduced between 2012 and 2013. A significant number of herbs have been introduced to the subsurface alongside young arboreal trees species such as Bumalda bladdernut, Acer triflorum, Cornus controversa etc and shrubs. However, many woody species did not survive the competition with herbs and repeated withering and regeneration. The number of woody species generated within the 30% cutting area was 440 species in 2013 and this figure has been increasing twofold each year. The number of woody plants within the 50% cutting area also showed an upward tendency and most plants did not survive in the competition with herbs and Sasa borealis and withered in only 1 ~ 2 years after generation. Unlike other thinning areas, the 70% cutting area showed 608 broadleaved trees, reflecting a decrease from 748 trees in 2012. This appeared to be attributed to the luxuriance of S. borealis and the sharp increase of fatsia following the inflow of total sunlight to the forest floor. Herbs were hardly generated due to the influence of S. borealis. Regarding the density for thinning at 50% or upper height, the forest treatment division shall maintain a proper density in the course of inducing artificial forestation of larch into natural broadleaved forests considering the luxuriance of sasa borealis and herbs due to the inflow of total sunlight to the forest floor.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.5
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• pp.28-41
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• 2009

Because fire has significant impacts on fauna and flora in forest ecosystems, as well as socioeconomic influences to local community, it has been an important field of study for decades. One of the most common ways to reduce fire risk is to enhance fire-resilience of forest through fuel treatments including thinning and prescribed burning. Since fuel treatment can't be practiced over all forested areas, appropriate and effective strategies are needed. The present study aims to look at the relationship between spatial characteristics of forest structure measured with landscape pattern metrics and burn severity to provide guidelines for effective fuel treatments. Samchuck fire was selected for the study, and 232 grids covering the study areas were generated, and the grid size was 1km. The burn severity is measured with dNBR derived from satellite imagery, and spatial characteristics of forest structure were measured using FRAGSTATS for both landscape and class levels for each 1km grid. The results of this study strongly indicated that heterogeneity in composition and configuration of forests may significantly reduce burn severity. By enhancing heterogeneity of forests, fuel treatments for fire-resilience forest could be more effective.

• Journal of Korean Society of Forest Science
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• v.99 no.2
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• pp.251-257
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• 2010

Influences of environment (indicated by plant associations) and forest management practices on the distribution of Armillaria spp. and genets (vegetative clones) were investigated. A total of 142 isolates of Armillaria was collected from various host trees on pristine and managed sites (thinned and/or fertilized) growing in relatively wet and dry environments in eastern Washington, U.S.A. The incidence of Armillaria spp. was significantly higher in the relatively wetter sites than the relatively drier sites, as indicated by plant associations. However, no differences in Armillaria occurrence were found among different forest management practices (control vs. thinned vs. thinned and fertilized) within both wetter and drier sites. Incidence of Armillaria was significantly different among conifer and shrub species. The highest proportion with Armillaria was found on grand fir (Abies grandis). Based on pairing tests and rDNA sequencing, the 142 isolates were comprised in a total of 20 genets representing three Armillaria species. More diverse Armillaria spp. were found in both relatively wetter and relatively drier sites within the undisturbed control plots, compared to plots disturbed by forest management practices. The results from this study provide baseline information toward understanding how environment and forest management practices influence incidence and diversity of Armillaria species and genets.

• Journal of Forest and Environmental Science
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• v.30 no.4
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• pp.362-369
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• 2014

This study investigated physical properties and combustion gas characteristics for 8 types of wood pellets (4 domestic and 4 imported products) distributed in the domestic market. Results showed that most pellet types were first-grade pellets in the wood pellet quality standards in Korea with the exception of 3 pellet types from K company (second-grade in mechanical durability), G company (off-grade in nitrogen content) and P company (second-grade in ash percentage). Mixed pellets which contained more lignin and sap content were higher in mechanical durability (%) than that of white pellets. From the combustion gas analysis results, NOx emitted from all pellets combustion was at acceptable levels for national emission standard of the Clean Air Conservation Act except for pellets from G company. In addition, CO levels from all types of wood pellets were acceptable except for pellets from D company and domestic pellets were higher CO levels than imported pellets. These results indicate the higher CO levels in domestic pellets due to the usage of forest thinning materials including logging debris which usually had the high content of bark.

• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.604-619
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• 2012

According to the concept of woodland aesthetic in Germany and forest design in United Kingdom, artificial forest should be restore ecologically step by step in National Park, Korea. This study was carried out to provide the density criterion of thinning for the inducement of the ecological succession by analysing of vegetational structure in Artificial Forest, National Parks. Eleven plots(size is $20m{\times}20m$) were set up in the artificial forest such as Pinus koraiensis forest, Abies holophylla forest, Chamaecyparis obtusa forest, Populus tomentiglandulosa forest, and Larix kaempferi forest and in the natural forest such as Pinus densiflora community, Pinus densiflora-Quercus serrata community, and Quercus serrata community in Chiaksan, Songnisan, Deogyusan, and Naejangsan National Parks, Korea. We classified the artificial forest into undeveloped type of succession, type of alien young trees developing, and early phase type of succession based on the vegetational structure. According to the index of Shnnon's diversity(unit: $400m^2$), undeveloped type of succession was ranged from 0.9681 to 1.1323, type of alien young trees developing was ranged from 1.0192 to 1.1870, early phase type of succession was ranged from 1.3071 to 1.3892, and natural vegetation was ranged from 1.2202 to 1.3428, therefore early phase type of succession forest and natural vegetation are more higher than simple-layered artificial forest with one needle leaf tree species. The limit for the step-by-step thinning was in the range of 30~60%. In case of undeveloped type of succession, we should thin out from large trees throughout three phases, because alien species dominated high value 88~90% in canopy layer. In case of type of alien young trees developing, we should thin out from alien young trees such as Populus tomentiglandulosa throughout one or two phases, because alien species dominated high value 60~97% and young trees with saplings growing up in understory and shrub layer. In case of early phase type of succession, we should thin out from alien trees that compete with native species throughout one or two phases, because alien species dominated less than value 30%.