• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.4
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• pp.222-228
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• 2012

This study was conducted to determine the natural succession process after forest fire by comparing height, relative growth rates in height (RGH), and tree density of pine seedlings with different fire severity. In the area damaged by surface fire, tree density was highest during the first 5 years after fire. However, in the area damaged by crown fire, tree density rapidly increased during first 5 years after fire. Pine seedlings were found only on the place with ridges, barren soil, and the aspect of north. Annual height growth of pine seedlings was decreased with time in all study sites. The empty space in pine stands gradually decreased by the invasion of Quercus species. The forest fire altered the pine forest into oak forest rapidly. In contrast, pine seedlings invaded steadily on the oak forest in the rocky area or the area with ridges.

• Korean journal of applied entomology
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• v.56 no.1
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• pp.41-49
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• 2017

The community of xylophagous beetles belonging to Cerambycidae, Curculionidae and Scolytinae in Korean white pine, Pinus koraiensis Siebold & Zuccarini, forests was surveyed using Malaise traps in 2007. A total of 1,615 xylophagous beetles were collected, including 184 cerambycids from 15 species, 185 curculionids from 17 species, and 1,246 scolytid beetles from 6 species, of which the dominant species was the ambrosia beetle Xyleborus mutilatus Blandford. Ranked by order of population size, the wood-boring and bark beetle community in Korean white pine showed high dominance by one species of Scolytinae, suggesting the community had low biological diversity. Thinning in Korean white pine forests influenced on the abundance of bark and ambrosia beetles, whose populations in particular stands increased 1 year after thinning, and then decreased the following year.

• The Korean Journal of Ecology
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• v.17 no.4
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• pp.501-511
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• 1994

Dynamics of nutrients, non-polar, water solubles, acid solubles and acid insolubles (lignin) in decomposing litter were investigated for 2 years in the oak, Quercus acutissima, and the pitch pine, Pinus rigida, stands in the vicinity of Kongju, Chungnam Province. Nitrogen and phosphorus conetrations in decomposing litter increased with time elapsed, however, potassium decreased rapidly within three months and then remined constant with time elapsed. Calcium concentration in needle litter during experimental period was lower than that of initial concentration in needle litter during experimental period was lower than that of initial concentration, and showed no significant variation with time elapsed. Calcium concentration in oak litter during the experimental period, however, were higher than that of initial concentration. Magnesium concentration in oak litter decreased repidly during six months, and then remaines constant thereafter. Annual amount of nitrogen, phosphorus, potassium, calcium and magnesium which returned to soil via litter decomposition in the oak and the pitch pine stands was $3.3g/m^2$ and $0.9g/m^2$ for N, $0.03g/m^2$ and $0.01g/m^2$ for P, $1.3g/m^2$ and $0.7g/m^2$ for K, $0.7g/m^2$ and $1.2g/m^2$ for Ca, $0.9g/m^2$ and $0.4g/m^2$ for Mg, respectively. Non-polar, and water- and acid-soluble fractions in decomposing litter decreased and lignin increased with time.

• Journal of Korean Society of Forest Science
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• v.84 no.2
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• pp.258-265
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• 1995

Regeneration process of edaphic pine(Pinus densiflora) climax forest in Bulyung-gyegog, Uljin-gun, Kyungsangbuk-do, was studied. The height of dominant trees in the stands are 12 15m. Upper layers are highly dominated by pine trees and are randomly distributed. Pine trees in lower layer grow in a patch type. In the upper layer, the age distribution is likely one model type with mode of 60 and 80 years. In the horizontal distribution of these trees, some of the even-aged cluster constituted of several tree were found. For the first 25 years, the stem diameter increment rates in upper layer are higher than those in the middle layer. It could be concluded that after the forest canopy had been broken out, the seedlings established densely in a patch in the gap with the decreasing density and some of them, distributed in random, would constitute the canopy.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.4
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• pp.59-67
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• 2020

In this study, the effects of windbreak fences composed of natural vegetation on one-year-old seedlings were analyzed to develop restoration methods for an endangered subalpine species, the dwarf Siberian pine (Pinus pumila (Pall.) Regel). One-year-old seedlings were planted in 2016 by sowing seeds that had been collected from the Daecheongbong area on Mt. Seoraksan, South Korea, in 2014. The area near Daecheongbong was selected as the experimental site, and treatment and control plots (2m×2m) were installed at the site. To analyze the effects of wind protection, windbreak fences were constructed in the treatment plots using hairy Korean rhododendrons (Rhododendron mucronulatum Turcz. var. ciliatum Nakai) from the surrounding area and weather stations were installed to investigate atmospheric temperature, humidity, and wind speed. In all control plots without windbreak fences, dwarf Siberian pine seedlings were killed by strong winds seven months after planting. In contrast, the average survival rate of the seedlings in treatment plots was 96.7% after seven months, 64.2% after two years, and 45% after three years, with most (85.3%) of the seedlings showing good initial root establishment. Accordingly, windbreak fences composed of natural vegetation are suitable for promoting the early establishment of seedlings in the restoration of dwarf Siberian pine stands.

• Journal of Korean Society of Forest Science
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• v.98 no.4
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• pp.451-457
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• 2009

This study was conducted to evaluate the felling productivity by chain saw in thinning operation of Korean pine (Pinus koraiensis) stands. Time study data were collected from 4 thinning site in Korean pine stands. This study derived a regression model to estimate the average felling cycle time for evaluating the productivity in felling, which was used to analyze the felling productivity by thinning period. In the study sites, the average felling cycle time per a tree was 463 sec/cycle and the productivity was $2.26m^3/hr$. Thinning period in Korean pine is divided into three groups by producing purposes; small-diameter log, medium-diameter log, and large-diameter log. And analyzed working time and productivity from thinning period fixed by producing purposes. For the small-diameter log producing purpose estimated to be thinning period operated once when the mean DBH was 16 cm and its productivity was $8.94m^3/man{\cdot}day$. For the medium-diameter and large-diameter log producing purposes, thinning period was twice and three times when the mean DBH of the 1st and 2nd thinning period was 16 cm and 21 cm, and its productivity was $9.06m^3/man{\cdot}day$ and $10.86m^3/man{\cdot}day$. The 30 cm in DBH and $15.12m^3/man{\cdot}day$ in productivity was operated 3rd thinning for the large-diameter log producing purposes.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.3
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• pp.117-128
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• 2023

Tree dieback in Geumgang pine forest has occurred in Uljin and Bonghwa since the 2010s. In order to identify status of tree dieback and prevent further damages, a monitoring project for tree dieback in Geumgang pine forest had been launched by Southern regional office of forest service in 2020. This study was conducted to understand the characteristics of tree dieback occurrence and assess the high risk areas using the occurrence data in the project. Pine tree dieback occurred frequently in areas with mountain ridges in high elevation, dry south-facing slopes, mature stands, and high temperature rise in winter. Furthermore, the result of risk assessment showed that 6.2 percent(5,294ha) of Geumgang pine forest(85,000 ha) in total study area are at high risk of tree dieback. As the pine trees in the high risk area are prone to experience the dieback due to temperature and drought-related extreme weather events, regular forest management activities are needed to reduce the drought stress of pine trees. Forest health management for the pine forest with high protection priority can be also useful strategy to counter the risk of decline. This results can be used as the basic information for the adaptive forest management to climate change.

• Journal of Ecology and Environment
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• v.30 no.4
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• pp.281-285
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• 2007

We conducted research to determine the effects of forest tending works (FTW) on forest carbon (C) storage in Korean red pine forests by estimating changes in the quantity and distribution of stored organic C in an approximately 40-year-old red pine stand after FTW. We measured organic C storage (above- and belowground biomass C, forest floor C, and soil C at 50 cm depth) in the Hwangmaesan Soopkakkugi model forest in Sancheonggun, Gyeongsangnam-do before and after the forest was thinned from a density of 908 trees/ha to 367 trees/ha. The total C stored in tree biomass was 69.5 Mg C/ha before FTW and 38.6 Mg C/ha after FTW. The change in total C storage in tree biomass primarily resulted from the loss of 19.9 Mg C/ha stored in stem biomass after FTW. The total C pool in this red pine stand was 276 Mg C/ha before FTW and 245.1 Mg C/ha after FTW. Prior to FTW, 71.5% of the total C pool was stored in mineral soil, 25.2% in tree biomass, and 3.3% in the forest floor, where as after FTW 80.5% of the total C pool was stored in mineral soil, 15.7% in tree biomass and 3.7% in the forest floor. These results suggest that the development of site-specific tending techniques may be required to minimize the loss of tree biomass C storage capacity in red pine stands from FTW.

• The Plant Pathology Journal
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• v.39 no.3
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• pp.290-302
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• 2023

Abamectin offers great protection against Bursaphelenchus xylophilus, a well-known devastating pathogen of pine tree stands. Trunk injection of nematicides is currently the most preferred method of control. This study aimed to evaluate the potency of the commonly used formulations of abamectin against B. xylophilus. Twenty-one formulations of abamectin were evaluated by comparing their sublethal toxicities and reproduction inhibition potentials against B. xylophilus. Nematodes were treated with diluted formulation concentrations in multi-well culture plates. And, populations preexposed to pre-determined concentrations of the formulations were inoculated onto Botrytis cinerea culture, and in pine twig cuttings. Potency was contrastingly different among formulations, with LC₉₅ of 0.00285 and 0.39462 mg/ml for the most, and the least potent formulation, respectively. Paralysis generally occurred at an application dose of 0.06 ㎍/ml or higher, and formulations with high sublethal toxicities caused significant paralysis levels at the tested doses, albeit the variations. Nematode reproduction was evident at lower doses of 0.00053-0.0006 ㎍/ml both on Botrytis cinerea and pine twigs, with significant variations among formulations. Thus, the study highlighted the inconsistencies in the potency of similar product formulations with the same active ingredient concentration against the target organism, and the need to analyze the potential antagonistic effects of the additives used in formulations.

• Journal of Korean Society of Forest Science
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• v.61 no.1
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• pp.1-7
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• 1983

In the estimation of diameter distribution in a stand using Weibull distribution function, the calculation method of experimental distribution was presented in previous paper. This study was to estimate the diameter distribution of Korean pine stands by Weibull distribution which represents Gamma function, with mean diameter and mean basal-area diameter of the random sample trees. The results obtained fitted the diameter distribution in experimental stands. Thus, this method appears to be used for the estimation of diameter distribution in a stand as well as for the analysis and prediction of stand construction for the future.