• Journal of Korean Society of Forest Science
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• v.106 no.4
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• pp.480-486
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• 2017

This study was conducted to develop the merchantable stem volume models to predict the volume up to upper diameter or upper height out of the total stem volume, targeting on Pinus densiflora, Pinus koraiensis, and Larix kaempferi in South Korea. The 131 stemmed sample trees for stem analysis were used as the data for developing the models. The six kinds of merchantable volume equations including merchantable volume ratio form, ratio form, and exponential ratio form were examined to develop the best models. The two models were finally selected as the best models to predict the merchantable volume: $V_d=V_t\{{\exp}[{\alpha}_1(d^{{\alpha}_2}/D^{{\alpha}_3})]\}$ for upper diameter and $V_h=V_t\{1+{\beta}_1(P^{{\beta}_2}/H^{{\beta}_3})\}$ for upper height. By rearranging the best model equations, implicit taper functions were derived, and the estimation was performed for the upper height by upper diameter and upper diameter by upper height. Because of not only the high accuracy but also the convenience, the models developed in this study were considered to be easily applicable in the field of forestry.

• Journal of Korean Society of Forest Science
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• v.102 no.1
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• pp.24-29
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• 2013

This study was carried out for preliminary feasibility review to investigate work efficiency of chestnut harvest using yield net and to find a way to reduce the cost for purchasing and managing yield net. To this end, we conducted a survey of 6 forest farm houses in Cheongyang, Gongju and Buyeo regions where yield nets are being used efficiently. Cost-benefit analysis based on Net Present Value and Benefit Cost Ratio was used to examine the investment profitability. While regions of Cheongyang A, Cheongyang B and Buyeo A are profitable in spite of no subsidy for purchasing yield net from the government, the regions of Gongju A, Gongju B and Buyeo B are not profitable without subsidy. When an 80% of subsidy for purchasing yield nets is provided, the forest farm houses in Cheongyang A, Cheongyang B, Buyeo A and Gongju B regions are found to be profitable while those in Gongju A and Buyeo B regions are still not profitable. We consider that the different results come from the differences in the planting method of chestnut, labor efficiency, labor skill and the orchard conditions such as slop. Finally, several efforts for government and cultivator are suggested to expand the use of yield net; planting chestnut in line, establishing installation and management methods, supporting the cost for purchasing yield net and studying detailed effects besides profitability issue.

• Journal of Mushroom
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• v.15 no.4
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• pp.216-222
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• 2017

This study was conducted to investigate the proximate composition, free sugars, amino acids, and minerals in five Lentinula edodes cultivars collected in Korea. No significant differences in the content of crude fat and crude fiber were found between the samples; however, there was significant variation in the contents of nitrogen free extract, ash, and crude protein. Three kinds of free sugars (fucose, arabinose, and glucose) were identified by HPLC, with the glucose content ranging from 5.94% to 12.08%. Sixteen kinds of free amino acids were identified: the highest content of amino acids was found in 'Sanlim5ho' (13,768.33 mg%), while the highest content of free amino acids was found in 'Sanlim4ho' (6,790.57 mg%). The minerals detected in the L. edodes cultivars were potassium, calcium, magnesium, and sodium, the contents of which ranged from 567.16-2,356.09 mg%, 3.85-7.42 mg%, 9.79-20.88 mg%, and 19.60-22.62 mg%, respectively.

• The Journal of Engineering Geology
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• v.27 no.4
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• pp.393-403
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• 2017

Mountain disasters in Korea have caused massive social and economic damage. During the period 2005-2014 there has been an annual average of 7 deaths and disaster recovery costs of 79.8 billion won in the country's 4393 ha of mountainous areas. The primary mountain disasters are landslides on mountain slopes, and secondary debris flows can spread along mountain streams, damaging facilities and settlements in lower areas. Typhoons and local rainfall can cause such disasters, while anthropogenic factors include development that damages the mountainous terrain. The study area was divided into three basins. For each basin, a debris flow vulnerability assessment method was proposed considering FLO-2D analysis results and the local topography, geology, and forestation. To establish an in situ investigation, analysis, and evaluation plan for potential mountain disasters, we selected mountain basins that are potentially vulnerable to mountain disasters through analysis of their mountain slopes and streams. This work suggests the establishment of a comprehensive plan for disaster prevention based on a mountain basin feature.

• Korean Journal of Plant Resources
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• v.33 no.5
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• pp.419-427
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• 2020

Ligusticum chuanxiong Hort. is included in Umbelliferae family, it is one of the Korean traditional medicinal plants as the roots have been used to treat diseases. In this study, the growth characteristics and active compound contents of L. chuanxiong were compared among the different forest sites. As a result, root diameter and root length of L. chuanxiong was the highest in Jeongseon. Also, the fresh weight and dry weight of L. chuanxiong were the highest in Jeongseon. The total content of active compound was 23.27 mg/g the highest in Bonghwa, and 21.59 mg/g in Jeongseon, 15.87 mg/g in Hamyang was accumulated. In this study compares three forest site for cultivating of L. chuanxiong in different climate zone that the best site to product yield were Jeongseon. In this sites were located in higher altitue and lower temperature than other sites, also there were shown that lower soil moisture contents and well-drained soil. It was shown yield and active compound contents of L. chuanxiong was influenced by micro-environment conditions like as altitude, temperature, soil conditions.

• Journal of Korean Society of Forest Science
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• v.103 no.4
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• pp.556-563
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• 2014

The purpose of this study was to evaluate the effects of container types on seedling growth of Chamaecyparis obtusa (2-year-old) in the container nursery culture. We used three container types [20 cavities (400 mL/cavity, $150seedlings/m^2$), 24 cavities (320 mL/cavity, $200seedlings/m^2$), and 35 cavities (240 mL/cavity, $260seedlings/m^2$)] and measured root collar diameter (RCD), height, biomass, root density and seedling quality index (SQI). The RCD, height, biomass, root density and SQI were the highest at 20 cavities/tray because this container has the largest volume and lowest seedling density. However, H/D and T/R ratio at all container types were not significantly different. The total biomass per unit area ($m^2$) were the lowest at 35 cavities/tray and those at both 20 and 24 cavities/tray were not significantly different. Container volume was positively correlated with RCD, height, biomass, root density and SQI except for H/D and T/R ratio, while seedling density negatively affected on them. Based on these results, 20 cavities/tray are optimal for container seedling production of C. obtusa. Usage of optimal container will make us get better quality seedlings and reduction of production costs in the container nursery as well as good field performances with higher survival rate in plantation.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.324-332
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• 2012

The purpose of this study was to evaluate the effects of container types on seedling growth of Betula costata, Liriodendron tulipifera, Fraxinus rhynchophylla, Fraxinus mandshurica, Zelkova serrata, and Ulmus parvifolia in the container nursery system. We used three container types [20 cavities (150 seedlings/$m^2$-400 mL), 24 cavities (200 seedlings/$m^2$-320 mL), and 35 cavities (260 seedlings/$m^2$-240 mL)] and measured root collar diameter (RCD), height, biomass, seedling quality index (SQI), and root density. The root collar diameter, height, biomass, SQI, and root density of seedlings were the highest at 20 cavities/tray in all six species because this container type has the largest volume and lowest seedling density. However, F. rhynchophylla growth at both 20 and 24 cavities/tray, Z. serrata growth at both 24 and 35 cavities/tray and B. costata growth at all sizes were not significantly different. As expected, container volume was positively correlated with RCD, height, and biomass of five species except for Z. serrata, but seedling density negatively did. Based on these results, 20 cavities/tray are optimal for L. tulipifera, F. mandshurica, and U. parvifolia, 20 or 24 cavities/tray for F. rhynchophylla, 24 or 35 cavities/tray for Z. serrata, and 35 cavities/tray for B. costata, respectively. Usage of optimal container will make us get good quality seedlings as well as reduction of production costs in the container nursery.

• Korean journal of applied entomology
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• v.58 no.4
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• pp.291-297
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• 2019

Since Metcalfa pruinosa was first reported in Koera, it has continually caused damage to sweet persimmon orchard in southern part of Korea. Metcafa pruinosa exist not only in farmland but also in forest areas, and are difficult to control due to the influx of individuals from near forest. M. pruinosa has been occurred in orchard and its surroundings because of various host range. Thus, it has been difficult to decide spatial range and control time for efficient management. In this study, occurrence and dispersal pattern of M. pruinosa in persimmon orchard were surveyed using clear sticky traps, and spatial patterns were analyzed with SADIE(Spatial Analysis by Distance IndicEs), based on location information at sticky traps. Spatial association between survey time was also analyzed to identify when the spatial pattern changed. In sweet persimmon orchard, M. pruinosa mainly dispersed in mid to late May, when the first instar hatches, and in August, emerging season of adult. The first instar nymphs hatched in mid-May were randomly distributed in orchard, but distribution was changed to aggregative pattern after dispersed surroundings of orchard. Adults showed random distribution pattern after immigration to orchard again. These tendency was also observed in density change at orchard and its surroundings, and matched to actual density of M. pruinosa in sweet persimmon trees.

• Journal of Korean Society of Forest Science
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• v.105 no.2
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• pp.231-237
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• 2016

This research was conducted in order to examine whether the Woodgrab short-wood logging method, most widely used logging method in Korea, is more favorable than other logging methods in terms of productivity and profitability. For the comparative purposes, whole-tree logging methods with cable yarding system using a swing yarder and a tower yarder were evaluated. The productivity and the profitability of the logging operations by the machine types on a L. kaempferi stand were estimated by simulating logging processes based on bucking patterns and the results were compared. As a result, the Woodgrab short-wood logging system showed the most favorable results in terms of skidding productivity and operating cost. On the contrary, the system was the least profitable among the three logging methods. Main reason is that while the system may be beneficial in terms of operation productivity, it is restricted to produce only short logs mainly for low quality raw materials such as pulp, bolts, etc. which are sold at cheap prices.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.136-143
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• 2010

This study was conducted to provide basic information on the management of natural deciduous forests by presenting suitable stand density over time for natural deciduous forests in Pyungchang Area. The stand density index(SDI) for the sampling point was also computed. The cutting scenarios were adopted by considering the SDI estimated in the sampling point. And then, simulation cutting was enforced to the stand. Cutting scenarios consisted of three cutting levels, with the period of 5 years where each suitable cutting level of selection system will not have the SDI over the maximum SDI throughout 30 years and consider harvest after 30 years. As a result of the simulation cutting, it was found that removing 12% and 14% of basal area per each time kept proper stand density while removing 10% exceed to the adequate basis. From an economic point of view, it was concluded that removal 12% of basal area would be the most suit cutting level in selection system.