• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.328-333
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• 1998

To obtain basic information for establishing a pest control strategy for insect pest management system, changes in the population densities of the black-tipped sawfly(Acantholyda posticalis posticalis Matsumura) and damage patterns in tree growth were investigated in national forests in Hoigok-ri, Kapyung-gun, Kyunggi-do, where the pest control measures were taken. The results obtained were as follows ; 1. The larval density in the soil of the forests where the insecticides were applied have been kept below economic threshold for about 7 years. The density was the highest in the middle of slopes and similar to the level of the early stage of the insect outbreak. 2. After the pest control by insecticides, reduction in tree height and diameter growth lasted for 2-3 years in trees defoliated by over 70%. 3. The diameter growth of the trees damaged by black-tipped sawfly recovered faster in upper stem than in the lower. 4. volume growth of the trees defoliated over 70% by the insect decreased for three to four years. The volume loss of trees defoliated by 70% and 90% was 19.6% and 54.0%, respectively. 5. Maintaining the rate of defoliation below 50%, which is the economic threshold, by chemical control measures had an effect of reducing the tree volume loss by $40m^2/ha$ as compared with a stand defoliated by 90%.

• Journal of Korean Society of Forest Science
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• v.80 no.1
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• pp.82-96
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• 1991

This study was carried out to investigate the structural characteristics of Coleoptera communities inhabiting the crowns of the Korean pine(Pinus koraiensis S. et Z.). Four plantations of the Korean pine, stand A (11 years old), stand B(21 years old), stand C(31 years old), and stand D(46 years old), were selected in Sudong-myen, Namyangju-gun, Kyeonggi-do. Sampling was done by knock down methods using insectide(DDVP), which was conducted from April, 1986 to September, 1987, except for the winter season. The following major conclusions are drawn from this study : 1. The total number of Coleoptera was 107 species of 85 genera in 35 families : 83 species of 66 genera in 27 families in 1986 and 74 species of 52 genera in 30 families in 1987. 2. The abundant families, based on the number of species, were Staphylinidae (16.8%), Coccinellidae(7.5%), Chrysomlidae(6.5%), Curculionidae(6.5.%), and Cerambycidae(5.6%). These five families occupied 43.0% of the total number of species. 3. The important families, based on the number of individuals, were Cantharidae(28.2%), Catopidae(27.7%), and Coccinellidae(23.0%). These three families occupied 78.9% of the total number of individuals. 4. The important species, based on the number of individuals, were Podabrus sp. (22.6%, C-antharidae), Catnps sp. 1 (21.7%. Catopidae), Anatis halonis (15.2%. Coccinellidae). Dominant species was Podabrus sp. (25.2% in 1986 and Catops sp. 1(24.9%) in 1987. 5. Generally, more spices and individual numbers were found in older stands than in younger ones. 6. The Coleoptera communities decreased in the thinned stand (stand C). Such a phenomenon in the thinned stand was likely to last two or more years. 7. The Coleoptera communities reached their peak of abundance in May, and decreased thereafter.

• The Korean Journal of Mycology
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• v.15 no.1
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• pp.48-69
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• 1987

To understand host ranges and host specificity of ectomycorrhizal fungi and fungus specificity of host tree species, higher fungi from pure forest stands of following twelve tree species were collected for six years from 1981 to 1986: Pinus densiflora, P. rigida, P. koraiensis, Picea koraiensis, Larix leptolepis, Abies holophylla, Populus $alba{\times}glandulosa$, Castanea crenata, Quercus aliena, Q. acutissima, Q. mongolica, and Betula platyphylla. A total of 196 ectomycorrhizal species with 8 varieties in 48 genera were identified. Thirty-one species with one variety belonged to Russula, 22 species with 5 varieties to Amanita, 18 species with one variety to Lactarius. Fungi belonging to above three gepera, Laccaria, and Cantharellus had a relatively wide host range. Laccaria laccata was collected under all the 12 tree species, Amanita vaginata group under 11 tree species, Laccaria amethystina and Russula foetens under 10 tree species, Lactarius gerardii and Russula sororia under 9 tree species, and Amanita agglutinata, Cantharellus cibarius, Russula bella, and R. virescens under 8 tree species. Above 10 fungal species may be classified to have a wide host range. Following fungi were collected under 4 to 5 tree species of both conifers and broad-leaved trees: Amanita citrina, Boletus bicolor, B. erythropus, Lactarius piperatus, L. subzonar­ius, and Russula pseudodelica. Above fungi may be classified to have an intermediate host range. Chroogomphus, Gomphidius, Rhizopogon, and Suillus were collected only under Pinaceae and may be classified to have a narrow host range. Particularly Suillus grevillei was collected only under Larix leptolepis, and appeared to have high host specificity. A total of 83 ectomycorrhizal species were collected under Abies holophylla, 66 species under Pinus densiflora, 50 species under Pinus rigida, 49 species under Pinus koraiensis, 46 species under Quercus aliena, and 23 fungal species under Larix leptolepis. Particularly, Larix leptolepis was associated with different fungal flora, with fewer species of Amanita, Lactarius and Russula, and more species of Laccaria. Most host tree species surveyerl in the present study appeared to have low fungus specificity for ectomycorrhizal formation.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.344-390
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• 1977

The purpose of this paper was to schedule optimum cutting strategy which could maximize the total yield under certain restrictions on periodic timber removals and harvest areas from an industrial forest, based on a linear programming technique. Sensitivity of the regulation model to variations in restrictions has also been analyzed to get information on the changes of total yield in the planning period. The regulation procedure has been made on the experimental forest of the Agricultural College of Seoul National University. The forest is composed of 219 cutting units, and characterized by younger age group which is very common in Korea. The planning period is devided into 10 cutting periods of five years each, and cutting is permissible only on the stands of age groups 5-9. It is also assumed in the study that the subsequent forests are established immediately after cutting existing forests, non-stocked forest lands are planted in first cutting period, and established forests are fully stocked until next harvest. All feasible cutting regimes have been defined to each unit depending on their age groups. Total yield (Vi, k) of each regime expected in the planning period has been projected using stand yield tables and forest inventory data, and the regime which gives highest Vi, k has been selected as a optimum cutting regime. After calculating periodic yields and cutting areas, and total yield from the optimum regimes selected without any restrictions, the upper and lower limits of periodic yields(Vj-max, Vj-min) and those of periodic cutting areas (Aj-max, Aj-min) have been decided. The optimum regimes under such restrictions have been selected by linear programming. The results of the study may be summarized as follows:- 1. The fluctuations of periodic harvest yields and areas under cutting regimes selected without restrictions were very great, because of irregular composition of age classes and growing stocks of existing stands. About 68.8 percent of total yield is expected in period 10, while none of yield in periods 6 and 7. 2. After inspection of the above solution, restricted optimum cutting regimes were obtained under the restrictions of Amin=150 ha, Amax=400ha, $Vmin=5,000m^3$ and $Vmax=50,000m^3$, using LP regulation model. As a result, about $50,000m^3$ of stable harvest yield per period and a relatively balanced age group distribution is expected from period 5. In this case, the loss in total yield was about 29 percent of that of unrestricted regimes. 3. Thinning schedule could be easily treated by the model presented in the study, and the thinnings made it possible to select optimum regimes which might be effective for smoothing the wood flows, not to speak of increasing total yield in the planning period. 4. It was known that the stronger the restrictions becomes in the optimum solution the earlier the period comes in which balanced harvest yields and age group distribution can be formed. There was also a tendency in this particular case that the periodic yields were strongly affected by constraints, and the fluctuations of harvest areas depended upon the amount of periodic yields. 5. Because the total yield was decreased at the increasing rate with imposing stronger restrictions, the Joss would be very great where strict sustained yield and normal age group distribution are required in the earlier periods. 6. Total yield under the same restrictions in a period was increased by lowering the felling age and extending the range of cutting age groups. Therefore, it seemed to be advantageous for producing maximum timber yield to adopt wider range of cutting age groups with the lower limit at which the smallest utilization size of timber could be produced. 7. The LP regulation model presented in the study seemed to be useful in the Korean situation from the following point of view: (1) The model can provide forest managers with the solution of where, when, and how much to cut in order to best fulfill the owners objective. (2) Planning is visualized as a continuous process where new strateges are automatically evolved as changes in the forest environment are recognized. (3) The cost (measured as decrease in total yield) of imposing restrictions can be easily evaluated. (4) Thinning schedule can be treated without difficulty. (5) The model can be applied to irregular forests. (6) Traditional regulation methods can be rainforced by the model.

• Journal of Wetlands Research
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• v.14 no.1
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• pp.21-33
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• 2012

The dominant land use at the Seonakdong river watershed is paddy and forest areas and the Seonakdong river stands still. Thus, the water pollution in the Seonakdong river is becoming more serious for the non-point source. In this study, SWAT(Soil and Water Assessment Tool) model was evaluated for simulation of flow and water quality behaviors in Seonakdong river. To perform the calibration and verification of the SWAT model, the measurements of discharge and water quality were performed for the period from 2006 to 2007 at 5 gauging stations in Seonakdong river. The $R^2$ value for discharge and water quality were 0.86 and 0.70 respectively for calibration after the sensitive analysis. The $R^2$ value for discharge and water quality were 0.81 and 0.51 respectively for verification. The simulation results show that BOD value in the river tends to decrease after the opening of gates and the patterns of TN and TP concentrations are similar as that of BOD. The gate operators need to determine how to supply water in drought season for effective water quality improvement. This study shows that the SWAT model, which is capable of simulating hydrologic and water quality behaviors temporarily and spatially at watershed scale, could be used to get the gate operation rule for the water quality management in Seonakdong river.

• Korean Journal of Plant Resources
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• v.30 no.2
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• pp.176-190
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• 2017

South Korea is the northernmost distributional territory on the Camellietea japonicae (evergreen broad-leaved forests of the warm-temperate zone) in East Asia. A total of 40 stands were collected in terms of an ecologically-naturalized wild tea population (WTP), and their species composition was analyzed by $Z{\ddot{u}}rich$-Montpellier School's method with preliminary regard to forest canopy idendtification. Stand types were characterized by ecological flora's criteria such as Raunkiaer's life-form, neophyte, zonal distribution, and nativeness of species. Expansion of WTP distribution into the interior of the peninsula was recognized, than expected. The highest and northernmost WTPs have been recorded at Mt. Palgong, Daegu (390 m a.s.l.) and Iksan Jeonbuk (latitude $36^{\circ}$ 03' 33''), respectively. Altitudinal and latitudinal WTP distribution of Korea under continental climate shows lower than Japanese situation under oceanic climate. Community structure generally involved a few human interferences. Syngeographically WTP distribution was limited on the warm-temperate zone and the southernmost cool-temperate southern submontane zone. First driving force on distributional expansion of the WTP was anthropogenic, particularly in the northernmost distribution area. We finally confirmed an actual existence of the WTP in South Korea and suggested a long-term monitoring on the WTPs in national view of in-situ genetic resources with higher frost-resistance.

• Journal of Ecology and Environment
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• v.35 no.2
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• pp.123-129
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• 2012

Salt marsh is an important transitional zone among terrestrial, riverine, and marine ecosystems and is a productive habitat that interacts extensively with adjacent landscape elements of estuarine and coastal ecosystems. Nowadays, in addition to various human activities, a variety of natural processes induce changes in salt marshes. This study aims to provide background information to restore disturbed salt marshes and to propose their ecological restoration using seed banks. The study area is a prepared area for the Gwangyang Container Port located in the southern Korea. This area was formed by accumulating mud soils dredged from the bottom of the forward sea. This land was created in a serial process of preparing the Gwangyang container port and the salt marsh was passively restored by seeds buried in mud soil dredged from seabed. As a result of stand ordination based on vegetation data collected from the land, stands were arranged according to tolerance to salinity in the order of $Suaeda$ $maritima$, $Salicornia$ $europaea$, and $Phragmites$ $communis$ communities on the Axis 1. Landscape structure of the projected area was analyzed as well. Edges of the projected area were divided from the marginal waterway by the dike. Four types of vegetation appeared on the dike: $Alnus$ $firma$ plantation, $Robinia$ $pseudoacacia$ plantation, $Lespedeza$ $cyrtobotrya$ plantation, and grassland. In the more internal areas, two types of vegetation sequences appeared: $Aster$ $tripolium$ community-$Suaeda$ $glauca$ community-$Salicornia$ $europaea$ community sequence and $Aster$ $tripolium$ community-$Suaeda$ $maritima$ community-$S.$ $europaea$ community sequence. Mixed community showed the highest species diversity (H' = 0.86) and $S.$ $europaea$ community showed the lowest (H' = 0.0). Evenness is the highest in Mixed community (J' = 2.26) and the lowest in $S.$ $maritime-S.$ $europaea$ community (J' = 0.0). Several plant communities were successfully established on the land created by mud soil dredged from the bottom of Gwangyang Bay. Moreover, community diversity in this area approached a similar level with those from other studies involving natural salt marshes. Therefore, restoration effect based on community diversity obtained in our study can be evaluated as a successful achievement. In this respect, although most salt marshes in Korea and other places worldwide have been destroyed or disturbed by excessive land use, feasibility of seed bank as a restoration tool is greatly expected.

• Korean Journal of Plant Resources
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• v.31 no.5
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• pp.554-574
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• 2018

Mt. Bonghwa reaches a height of 800 m (2,870 ft) and stands on the flank of Mt. Daeam-san, which has an elevation of 1,304 m (4,278 ft). It is important to survey the flora of Bonghwa-san in that it is a way to make out what kind of plant species exist in DMZ due to the geographical characteristics of Bonghwa-san adjacent to Korean DMZ. Therefore this study was conducted to elucidate the distribution of vascular plants and their value of Bonghwa-san. The vascular plants that were collected 10 times from May 2015 to April 2017 consisted of a total of 525 taxa; 93 families, 309genera, 458 species, 4 subspecies, 58 varieties and 5 forms. The observed rare plant species as designated by Korea Forest Service were 12 taxa including Echinosophora koreensis, Epimedium koreanum, Anemone koraiensis etc. Endemic species were 16 taxa containing Cirsium setidens, Heloniopsis koreana, Salvia chanryoenica etc. 31 taxa were recorded as naturalized plants and their naturalized rate and urban index were noted as 5.8% and 7.25%. Among the surveyed 525 taxa, edible, medicinal, pasturing, ornamental, timber, dye, fiber and industrial plants included 213 taxa, 172 taxa, 196 taxa, 50 taxa, 23 taxa, 10 taxa, 6 taxa and 3 taxa, respectively.

• Journal of Korea Foresty Energy
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• v.21 no.3
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• pp.34-45
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• 2002

This study was carried out to investigate the diversity and frequency of ectomycorrhizal fungi by cutting levels in Quercus acuta and Pinus densiflora stands from June to October, 2001. The obtained results from investigation were as follows, 1. The total of fungi found during the surveyed periods were 50 species, 30 genus, 15 families. The fungi belonged to Agaricales(37 species, 18 genus, 7 families), Aphllophorales(7 species, 6 genus, 3 families), Auriculariales(1 species, 1 genus, 1 families) and Gasteromycetes(5 species, 5 genus, 4 families), Basidiomycota. 2. The total number of putative ectomycorrhizal fruiting bodies were 137 individuals, 22 species, 10 genus, 5 families, 79 individuals, 10 species, 6 genus, 3 families at strip-cutting area of Pinus densiflora stand, 24 individuals, 9 species, 5 genus, 4 families at strip-cutting area of Quercus acuta stand and 25 individuals, 10 species, 4 genus, 3 families at spacing cutting area of Quercus acuta stand. 3. Tylropilus neofelleus had high host specificity associated with Chamaecyparis obtusa, while Amanita pseudoporphyria had relatively wide host ranges compared to other ectomycorrhizal fungi. 4. The results analyzed by Correlation coefficients showed that relative humidity and precipitation were major enviromental factors to affect the distribution of ectomycorrhizal fruiting bodies.

• Journal of the Korean Wood Science and Technology
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• v.10 no.1
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• pp.38-46
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• 1982

The research was carried out to determine the division of juvenile and adult wood from the pattern of variables of wood quality indicators, to investigate general low of the size of juwenile wood and to study the characteristics of juvenile and adult wood. For this study some trees of Pinus koraiensis were selected and several wood quality indicators such as annual ring width. late wood percentage, tracheid length tracheid diameter, wall thicknes, and microfibril angles were measured. The results of this study were summaried as follows. 1) Juvenile and adult wood can be divided into radial variations of wood quality indicators. In this study juvenile wood might be classified as a large fluctuated region of radial wood quality variations in the nearest part to pith. 2) Juvenile wood was indicated as a part of nearly cylinderical shape, averaging 6-11cm in radius, near pith. 3) Number of rings from pith of juvenile wood was about 12-20 and was nearly constant in uniform growth trees among the forest stands. 4) Usually adult wood was formed within the about 5-10m above ground.