• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.179-188
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• 2020

Weeding refers to the process of removing weeds around crop trees, which cause competition in nutrients, moisture, and light, and has a great effect on the early growth and survival of crop trees for establishing forest resources. This study was conducted to find out the timing and method of weeding that is the most suitable for the major afforestation species in national forests. We investigated (1) weeding time and frequency for each afforestation species and (2) the height of crop trees and the length of weeds. Up to 99% weeding operation was carried out until 5 years following afforestation. Pinus densiflora, Larix kaempferi, Chamaecyparis obtusa, Prunus sargentii, and Betula platyphylla plantations accounted for more than 70% of the total weeding sites. Once-a-year weeding process was conducted from late June to late July (67%), and twice-a-year weeding process was the highest in June-August by 31%. Most species were shorter than the weeds until the first and second year of planting, but the height of the crop trees was higher than that of the weeds by 48% in average from the third year. Therefore, from the third year of afforestation, except for some species, it is possible to reduce the cost of weeding operations while reducing nutrient competition by the weeds through the removal of weed sprouts, mainly woody weeds, rather than clear cutting. This study contributes to efficiently develop forest resource establishment while reducing operational costs through a detailed weeding schedule and species-specific method.

• The Korean Journal of Mycology
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• v.20 no.1
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• pp.29-36
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• 1992

Glomus species forming sporocarps were collected at limestone areas in Danyang, on coal mine overburdens in Munkyung, on plantations of Celtis sinensis in the Jindo island and Cryptomeria japonica in the Namhae island, on the Ilchulbong crater base and at a shrubby land near the Chunjiyeon fall. One of the characteristics of Glomus clavisporum is the thick wall ($25-33{\mu}m$) of its cylinderic chlamydospores at the apex. G. heterosporum chlamydospores are loosely connected with each other through brown thick-walled hyphae. G. liquidambaris has paraphysis between chlamydospores. G. rubiforme is blackberry alike. G. sinuosum has a peridium composed of golden yellow thick-walled($2-3{\mu}m$) sinuous hyphae. G. taiwanense has red brown sporocarps with yellow spores of which wall is thickest at the apex.

• The Korean Journal of Ecology
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• v.27 no.3
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• pp.185-192
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• 2004

Vegetation established through the natural process, such as Quercus mongolica, Pinus densiflora, Q. variabilis, Q. acutissima, Carpinus laxiflora, Q. aliena and Q. serrata communities and artificially introduced vegetation, which are composed of Larix leptolepis and P. rigida plantations, are established in the mountainous land of the Mt. Songnisan National Park. On the other hand, the developed lands, which are consisted of agricultural folds, residential areas, commercial areas related to tourism, etc. appear in the lowland around streams. Based on the spatial distribution of vegetation, the southern district, which is attributed to Naesongni-myun by administrative system, showed higher natural degree and vegetation diversity. However, most of the other districts, which are attributed to Cheongcheon- and Chilseong-myuns, are covered with the Korean red pine forest, a product of artificial influence, and plantation also occupied higher percentage. Thereby both vegetation diversity and natural degree are lowering. A result of ordination by DCA showed that sands tended to be arranged by depending on the topographic condition. Species diversity of plant communities was higher in broad-leaved stands rather than in coniferous ones and in stands of the early stage than in ones of the late stage. The result of analysis on vegetation dynamics implied that vegetation of this region would be dominated by Carpinus laxiflora, Quercus mongolica and Pinus densiflora communities in the future. However, considered occurrence the of disturbance and response of vegetation on that, this estimation may different somewhat from an actual situation. Conservation strategies of the Mt. Songnisan National Park were discussed in viewpoints of landscape ecology, and conservation of major plant communities and biodiversity.

• Journal of Korean Society of Forest Science
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• v.102 no.3
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• pp.455-462
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• 2013

The objectives of this study were to compare soil physical and chemical properties and early growth of Pinus densiflora and Larix kaempferi seedlings in harvested Larix kaempferi and Pinus rigida stands. Study stands were located in harvested L. kaempferi (Yeongju) and Pinus rigida (Wonju) plantations. Seedlings of L. kaempferi (1-1) and P. densiflora (1-0) were planted in April, 2008, Yeongju. Also, seedlings of L. kaempferi (1- 1) and P. densiflora (1-1) were planted with the density of 3,000 seedlings/ha in April, 2010, Wonju. We analyzed soil physical and chemical properties and the relative growth rate of seedlings using diameter at root collar and seedling height. Soil organic matter, total nitrogen and available phosphorus concentrations in harvested P. rigida stand were significantly higher than those in harvested L. kaempferi stand. The relative growth rate of P. densiflora seedlings with former stands were not significantly different. The relative growth rate of diameter at root collar of L. kaempferi seedling in harvested P. rigida stands were significantly higher than that in harvested L. kaempferi stand. Higher concentrations of organic matter, total nitrogen and available phosphorus in harvested P. rigida stand was probably positively affect to the early growth of seedlings.

• Journal of Korean Society of Forest Science
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• v.76 no.3
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• pp.200-205
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• 1987

This study was carried out to examine the proper site for Pinus rigida ${\times}$ P. taeda. The 91 sample plots ($20{\times}10m$) were selected from the plantations located in middle part of Korea. Soil, environmental and climatic factors were investigated and regressed on the growth of Pinus rigida ${\times}$ taeda. (1) The factors which influenced strongly on the growth were temperature, elevation, soil moisture, physiographic position, slope, soil depth, wind protection, soil compactness and soil organic matter contents in order. (2) The most effective factors among them were temperature, elevation, soil moisture and physiographic position. (3) General conditions of proper site for planting the hybrid pine were above $-8^{\circ}C$ in mean minimum temperature in January, below 200m in elevation, moderate soil moisture, and valley or flat area in physiographic position.

• Journal of Korean Society of Forest Science
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• v.39 no.1
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• pp.64-68
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• 1978

Thirty nine clones of ${\times}$Populus alba glandulosa were selected tentatively and planted in Hwasung in Kyunggi-do, Jinju in Kyungnam-do, Myongju in Kangweon-do. Height measurements after tree growing seasons, indicated significant differences between clones and locations. Interaction between clones and locations were not significant statistically. Among 39 clones, 65-29-19, 65-11-106, 67-47-10, 66-14-149, 64-6-44 were best performing clones. Height measurements in Hwasung Kyunggi, and Jinju Kyungnam were 3.83m, 4.02m respectively, while that in Myongju Kangweon was only 1.06m. Myongju plantation in Kangweon-do is located in altitude of 800m and its average annual temperature was $6.2^{\circ}C$. Retarded growth in this plantation is caused high altitude and low temperature of the plantation which resulted from nearly three monthes shorter growing period than two other plantations. It is also recommended that straightness of stem, branching, wood quality and insect and disease-resistance have to be considered as selection criteria along with growth performance.

• Journal of Korea Foresty Energy
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• v.20 no.2
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• pp.69-80
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• 2001

Larix kaemferi Carr. is one of main timber species in Korea that could be found in plantations and growing stands on all over the country The proper practice of thinning is one of very important techiques in silviculture, which greatly affects the quality and size of timber produced. Proper thinning period is considered to be important for maintaining stand growth before competition initiated. To investigate suitable thinning period, this study investigates the volume and radial growths of Larix kaemferi plantation in Mt. Worak located in the central part of Korea. The main findings and conclusions obtained from this study were as follow ; (1) The tree height curve equation for Larix kaemferi in Mt. Worak was calculated H=4.25783+0.80024D(H=Tree height, D=DBH). (2) To estimate tree volume for Larix kaemferi by DBH and tree height or only by DBH, regression equations were calculated as V=0.00147-0.002095D-0.000211H+0.00015D.H++$0.000744D^2$+$0.000008H^2$(V=Volume(($m^3$), H=Tree height(m), D=DBH(cm)), V=0.0000794-0.000512D+$0.000826D^2$. (3) The criteria of estimating thinning time of Larix kaemferi are the age when maximum tree height-MAI(mean annual increment) obtained and the age when annual DBH increments of dead trees decrease to below average. (4) The age of maximum tree height MAI was not significantly correlated with stocking. Therefore, it can not be used as a criterion for estimating thinning time of Larix kaemferi (5) The estimated thinning time equation of Larix kaemferi was obtained by regression analysis of the disk section collected from dead trees. The obtained equation is Y=0.2825+0.01752X(Y=Desirable thinning age, X=the sum total of nearest 4-trees interval(cm)). (6) General estimated thinning age of Larix kaemferi, which planted 3,086 stocks/ha, is concluded as 12 to 14 year.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.2
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• pp.175-180
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• 1992

The occurrence of internal cavity of in red ginseng is one of critical quality criteria. The occurrence of internal cavity mainly due to fresh ginseng character that is determined by growth conditions. Growth conditions and percent occurrence of internal cavity were investigated on various ginseng plantations for 6 years and the relation. ships among them were statistically analysed. In addition, field experiments were carried out seperately for the effect of special factors. 1. Internal cavity in red ginseng mainly occurred on area between central part and cortex part of tap root in red ginseng. It was suppose to be caused by characteristics of fresh ginseng. 2. Soil moisture decreased percent occurrence of internal cavity(PIC) above 27.5 % of PIC and increased below it. 3. The factors of shade structure with high intensity of light condition tend to increase PIC. PIC was decreased below 15.9 % of light transmittance rate and increased above it.

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.107-114
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• 2007

Establishments of the seedlings inside the natural forest from adjacent artificial forests would be an important factor in forest stand dynamics. This study was conducted to see the invasion of Korean pine (Pinus koraiensis) seedlings which is not native in this region, into the natural deciduous broad-leaved forest in Gwangneung, Korea. There is no mother tree at the I ha study site while the number of naturally regenerated P. koraiensis seedlings was 345 trees and 56% of them were clumped with more than two seedlings at each point. Applying the image segmentation method to IKONOS satellite image of January, 2003, the distance from the center of 1 ha study site to the nearest mother tree and plantation of Korean pine were 200 m and 270 m, respectively. The average height and root-collar diameter of the seedlings were 34 em and 7 mm, respectively and the age of 207 seedlings (60%) were below 5 years old. Most abundant range of soil moisture gradient and LAl (leaf area index) were from 16 to 20% and those of LAI were from 3.1 to 3.5. To understand the dynamics and seed dispersal pattern of Korean pine in the Gwangneung natural deciduous broad-leaved forests, additional studies not only long-term monitoring of growth and mortality of naturally regenerated Korean pine seedlings but also application of stable isotope analysis and molecular genetic techniques was recommended.

• Journal of Korean Society of Forest Science
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• v.96 no.3
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• pp.348-356
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• 2007

The purpose of this study is to give the results of economic feasibility of industrial forest plantations, and also A/R CDM project in Indonesia to investors. In order to analyze economic feasibility of the industrial forest plantation and A/R CDM project, this study comparatively analyzes the feasibility based on three following scenarios: industrial plantation type; A/R CDM type; combination type of industrial plantation and A/R CDM project. In the aspect of IRR, the combination type has 11 % while the industrial plantation type has 8%. If the price of timber increases USD $5/m^3$ (from the standard price: USD $30/m^3$ to USD $35/m^3$), IRR of the industrial plantation type will increase from 8% to 14%. This result shows us that the IRR of the industrial plantation type is very sensitive to the price of timber. There is no economic feasibility of A/R CDM project if the price of lCER is under USD 5. In addition, IRR of the A/R CDM project type is the same to IRR of industrial plantation type (8%) when the price of lCER is USD 10. Finally, the total investment expenditure on 12,000ha of the combination type is approximately 13 billion won while the industrial plantation type is 13.6 billion won. It takes 11 year to reach the turning point in terms of profitability of the combination type while the industrial plantation takes 13 year. Thus, the economic feasibility of the combination type is higher than the other types(industrial plantation type and A/R CDM project type).