• Journal of Forest and Environmental Science
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• v.23 no.2
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• pp.109-118
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• 2007

This study was conducted to provide the fundamental data of the policy plan for the security of forestry labour and the revitalization of forestry mechanization by analysing the status of forestry labor and the training plan. In forestry, the total number of employer and the labour cost have slightly increased annually, but the number of employer for timber harvesting has decreased. Therefore, the organization of expert forestry mechanization unit and the training of operator will be necessary. The number and person of forest management unit, the working days of the year and income have increased in Korea. However, the working days per month of forest management unit were only 15 days, which are only 180 days per year. In the results of the calculated number and person of forest management unit for the Korean forest tending volumes, about 349 forest management units are required. In case of adjusting 12 persons per 1 unit, 4,185 persons are required. In calculated results of the optimum forestry mechanization unit and member's number by the adjusting of tower yarder harvesting system for annual timber harvesting production volume, it was known to necessary the 250 forestry mechanization unit and the 1,250 members which are calculated at 5 persons per 1 group.

• Journal of Korean Society of Forest Science
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• v.108 no.1
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• pp.116-126
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• 2019

The production volume and amount of non-timber forest products in Korea has been on the increase for the past five years. In particular, the production amount of wild vegetables (edible mountain plants) is approximately KRW 400 billion as of 2017, accounting for 14 % of the total production amount of non-timber forest products. Among wild vegetables, especially the production volumes and amounts of bracken, saw-wort (Saussurea), and thistle have grown steadily. Nevertheless, severe price competition with cheap imports and little changes in the pattern of wild vegetable consumption may negatively affect the prices of domestic wild vegetables. This, in turn, can decrease the overall consumption of wild vegetables. Recently, however, consumers have preferred healthy food with increases in their income and interest in health. Therefore, now is a crucial time for the wild vegetable market. Accordingly, this study analyzed consumers' purchase and consumption behavior related to wild vegetables through a consumer survey to contribute to establishing various strategies and policies for promoting the consumption of these vegetables. Also, this study identified consumers' awareness and intention regarding wild vegetables by analyzing social big data. Different from previous studies, this study investigated consumers' awareness and intention by analyzing SNS social big data, as well as conducting a survey. The results of the study will help prioritize strategies and policies for boosting the consumption of wild vegetables.

• Journal of Korean Society of Forest Science
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• v.34 no.1
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• pp.21-30
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• 1977

Japanese larch (Larix leptolepis) is one of main timber species in Korea that could find much plantation and growing stands on all over the country. It is thought to be in meaningful that a guiding diagram for density control of Japanese larch stands is made to estimate easily the density conditions in the quantitaive, ecological and economic viewpoint. Sample plots for this study are selected from the stands that have not been thinned in recent years, and mean height, mean diameter, dominant height, tree numbers per hectare and stem volume of mean tree are calculated from the each sample plots among total 165 plots In this study, especially, the theory of slenderness of mean tree are applied, that have been identified through the results of the spacing trial. Relative growth characteristics of this species are calculated from the general logistic curve and its formula is $Y=ax^b$. Relatwion between the measured items are found out as follows: 1. Relation between the mean height and tree numbers per hectare by slender class is showing the high correlation as table 1 and fig. 2, and between mean diameter and tree numbers per hectare is also high correlation as table 1 and fig 3. 2. The stem volume can be correctly estimated from height in case that slender class may be known, as showing in table 3 and fig. 4. 3. The stem volume can be more correctly estimated from the relation with $D^2H$ as formula, $Log_e\;V=0.9569\;Log_eD^2H-9.8431$, and relation between stem volume of single tree or volume per hectare and tree numbers per hectare are as following formulas: $Log_e$ stem volume=9.5026-1.6800 $Log_e$ tree numbers per hectare $Log_e$ stem volume per hectare=9.4911-0.6784 $Log_e$ tree numbers per hectare. Stem volume of mean tree, tree numbers per hectare and stem volume per hectare correspond to the mean tree height are calculated to slender class as table 5, 6, 7. Through the above steps, the diagram for density control of Japanese larch are produced as fig. 9. It is thought that this diagram could be applied to control the density of Japanese larch stands.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.484-490
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• 2013

This study was conducted to develop a simulation model for estimating the amount of such products as round wood, dimension lumber and the residual wood biomass produced by processing the individual trees of Larix kaempferi. In the model, the stem volume is assessed using the taper equations of the species to estimate the stem forms. Then, the model simulates the conversion processes of logs to round wood or lumber and assesses the maximum amount of the wood products by the lumber dimensions or round wood size. Also the model provides information on the amount of residuals for kerf and slabs produced on the conversion processes for sawn timber or round wood. According to the results of an application of the model to a L. kaempferi process, the trees greater than 12 cm of DBH can be converted to logs for lumber or round wood production. For the trees, of which DBH is available for log conversion, the maximum amount of final products by dimensions were analyzed. In this analysis, production of the bigger dimension lumber was assumed to be preferred to that of the smaller or round wood. This model can be used for assesment of forest economic value through estimation of merchantable volume for the trees, and assessment of mill residues which has the potential to provide significant amount of feedstock for bioenergy production as well.

• Journal of Korean Society of Forest Science
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• v.65 no.1
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• pp.68-73
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• 1984

The purpose of this paper was to figure out the efficiencies of two sampling techniques, a simple random sampling and a two-stage P.P.S. (probability proportional to size) sampling, in estimating the volume of the mature coniferous stands near Salzburg, Austria. With black-and-white infrared photographs at a scale 1:10,000, the following four classes were considered; non-forest, young stands less than 40 years, mature beech and mature coniferous stands. After the classification, a field survey was carried out using a relascope with a BAF (basal area factor) 4. For the simple random sampling, 99 points were sampled, while for the P.P.S. sampling, 75 points were sampled in the mature coniferous stands. The following results were obtained. 1) The mean standing coniferous volume estimate was $422.0m^3/ha$ for the simple random sampling and $433.5m^3/ha$ for the P.P.S. sampling method. However, the difference was not statistically significant. 2) The required number of sampling points for a 5% sampling error were 170 for the two stage P.P.S. sampling, but 237 for the simple random sampling. 3) The two stage P.P.S. method reduced field survey time by 17% as compared to the simple random sampling.

• Journal of the Korean Wood Science and Technology
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• v.45 no.3
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• pp.327-334
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• 2017

This study was carried out to investigate the formaldehyde emission of building materials and effect of carbonized-board (c-board) on formaldehyde reduction using a chamber method. As a result, reduction performance of formaldehyde was in the order of c-board (90%), c-bamboo board (84%), diatomite-based panel (82%), allophane-based tile (78%), Pinus densiflora timber (58%), MDF (54%) and gypsum-based board (46%) for approximately 12 days. In $1.9m^3$ chamber filled with particleboard (PB), the formaldehyde reduction performance of c-board was significantly increased with increasing input amount of c-board for 68 days. In particular, the formaldehyde emissions can be reduced above 40% and 75% by input rate of 10% and 30% c-board, respectively, in given ratio of chamber volume and PB area.

• Journal of the Korea Furniture Society
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• v.18 no.4
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• pp.317-323
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• 2007

Almost all the people, particularly the rural people are directly dependent on the continued productivity of natural resources, like water, soils, forests and fisheries. But the overuse by the extremely high population pressures has degraded the natural resources into severe widespread deforestation. The degradation of natural resources, particularly the plant resources has been a great concern for socio-economic and sustainable development of the country. The Forests in Bangladesh have been depleted and degraded in volume, area, and quantity, thus requiring urgent forest protection by identifying the causes of forest loss. There are so many causes of deforestation and loss of genetic resources such as; the timber industry, which, legal or not, are cutting too many trees; indigenous forest dwellers, having their own types of problems; migrants, who, because of problems in their places of origin, have decided to move to the forests and the government through its Forest Department which is not able or willing to implement suitable policies to regulate the cutting trees and to prevent illegal cutting. Because it is a time consuming task to mitigate the first and second sets of factors, we recommend involving forest dwellers in forestry practices as much as possible and taking necessary steps to alleviate the third and fourth sets and thereby reduce the rate of forest depletion. Accordingly, a number of strategies that should be adopted to halt the loss of remaining forest cover are discussed.

• Journal of Ecology and Environment
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• v.35 no.3
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• pp.243-249
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• 2012

Biomass expansion factors, which convert timber volume (or dry weight) to biomass, are used for estimating the forest biomass and accounting for the carbon budget at a regional or national scale. We estimated the biomass conversion and expansion factors (BCEF), biomass expansion factors (BEF), root to shoot ratio (R), and ecosystem biomass expansion factor (EBEF) for Quercus mongolica Fisch. and Quercus variabilis Bl. forests based on publications in Korea. The mean BCEF, BEF, and R for Q. mongolica was 1.0383 Mg/$m^3$ (N = 27; standard deviation [SD], 0.5515), 1.3572 (N = 27; SD, 0.1355), and 0.2017 (N = 32; SD, 0.0447), respectively. The mean BCEF, BEF, and R for Q. variabilis was 0.7164 Mg/$m^3$ (N = 17; SD, 0.3232), 1.2464 (N = 17; SD, 0.0823), and 0.1660 (N = 8; SD, 0.0632), respectively. The mean EBEF, as a simple method for estimating the ground vegetation biomass, was 1.0216 (N = 7; SD, 0.0232) for Q. mongolica forest ecosystems, and 1.0496 (N = 8; SD, 0.0725) for Q. variabilis forest ecosystems. The biomass expansion factor values in this study may be better estimates of forest biomass in Q. mongolica or Q. variabilis forests of Korea compared with the default values given by the Intergovernmental Panel on Climate Change (IPCC).

• Journal of Korean Society of Forest Science
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• v.11 no.1
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• pp.25-32
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• 1970

Site-index curves for Pinus densiflora Sieb. et Zucc. grown in the middle part of Korea were developed from stem analysis data by a procedure of guide curve equation $Yt=K-ab^t$ (t=0, 1, 2, ${\cdots}{\cdots}$) and shown in Fig. 2. The stand density expressed as size-number criteria was calculated and the relation of number of tree per hectare and average DBH was presented in Fig. 3, in which soil fertility showed little effect. When this is compared to Reineke's density standards, the Pinus densiflora stand ranks high level of stocking density (Fig. 5). As a measure for estimating timber volume, the angle-summation technique revealed to result wider variation. Constructing hypothetical populations for appraising angle-summation technique, the significance of its application in silvicultural and ecological research are discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1164-1170
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• 2013

Since trees sequestrate carbon and reduce the level of its concentrations in the atmosphere, forests should be considered as carbon pools as well as timber producers. This study focuses on finding optimal harvest age when carbon sequestration from trees is accounted by forest managers. A dynamic programming employs a static volume matrix, and solves the harvest decision problems. If carbon value is accounted in a tree harvest decision model, the optimal harvest age increases. The harvest age of pine trees set by the government for national forests is longer than the optimal solution. It is possible to say that the managers of national forests put more values on the standing pine trees than the value of carbon sequestration. The regulation for private forests, on the other hand, ends up in a shorter harvest age than the optimal solution, and this discrepancy could lead to an inefficient private forest management.