• Journal of Korean Society of Forest Science
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• v.104 no.4
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• pp.536-542
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• 2015

This study was examined for the growth response of tree diameter and volume to thinning treatments from different thinning intensities using three long-term thinning trials for Japanese Evergreen Oak (Quercus acuta Thunb.) stands in Wando island, Korea. After thinning in 1999, annual tree growth of diameter and volume was highest in heavy thinned stands for individual tree and this growth pattern of thinning response showed similar tendency to the individual tree growth response in light thinned stands. By increasing diameter growth, the value of H/D ratio (HDR) as an indicator of stem form was properly decreased and improved up to 80%. Although there is significant growth response of basal area in both heavily and lightly thinned stands, the growth potential both of heavily and lightly thinned stands in total stand volume is not likely to reach at the level of unthinned stands because of basal area growth loss associated with both light and heavy thinnings.

• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.323-330
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• 2010

This study was undertaken to compare early growth characteristics, such as height, diameter at root collar (DRC), and the dry weights of stem, branches, needles and roots between naturally regenerated and planted stands of Pinus densiflora for. erecta in Dae-gi and Bo-gwang site, Gangwon province, Republic of Korea. Average DRC growth was similar between the naturally regenerated and the planted stands in Dae-gi area, however, difference was statistically significant (P<0.01) between the naturally regenerated and the planted stands in Bo-gwang area, 4.66 cm and 2.61 cm, respectively. Average height of the naturally regenerated stands was significantly greater (P<0.01) than that of planted stands in both Dae-gi and Bo-gwang areas. The composition ratio of the dry weights for each part of measured trees was the highest in the stem in the naturally regenerated stands, but in the planted stands, the needle was the highest in both sites. The root/shoot ratio in the Dae-gi and Bo-gwang areas in the planted stands were much greater than those in the naturally regenerated stands, 0.25-0.30 and 0.17-0.18, respectively. The ratio of needle to stem biomass (N/S), branch to stem biomass (B/S), and needle to branch biomass (N/B) was significantly greater in the planted stands than those in the naturally regenerated stands in both sites. The results of this study represent that the regeneration methods, natural and artificial regenerations, can have an influence on the early growth of P densiflora for. erecta. This results not only provide the need for a correct planting method, but also will be useful in studies on the environmental adaptability of trees.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.299-308
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• 2006

This study was conducted to investigate differences in energy content of Quercus mongolica stands in the Republic of Korea with respect to latitude and altitude. Study sites were located in Mt. Joongwang, Pyeongchang-gun, Gangwon-do (altitude 1,300 m, 1,000 m, 800 m), Mt. Taehwa, Gwangju-gun, Gyeonggi-do (altitude 350 m), Mt. Wolak, Jecheon-si, Chungcheongbuk-do (altitude 300 m), Mt. Baekwoon, Gwangyang-gun, Jeollanam-do (altitude 800 m), and Mt. Halla, Jeju-do (altitude 1,000 m) by northern and southern aspect. Total energy content and annual energy fixation of Q. mongolica stands were 2,916-6,550 GJ/ha and 250-440 GJ/ha, respectively during the study period, Lower latitude (NE) stands of Q. mongolica showed more energy contents and annual energy fixation than higher latitude stands. Energy content and annual energy fixation of Q. mongolica stands were increased in low altitude. Energy content of Q. mongolica stands were higher in northern aspect than southern aspect. However, there were no significant differences in annual energy fixation between the aspects. Annual energy fixation of Q. mongolica stands was highly correlated with warm index and followed by descending orders: altitude, stand age, aspect, annual solar radiation and latitude.

• Journal of People, Plants, and Environment
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• v.24 no.6
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• pp.629-638
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• 2021

Background and objective: This study was conducted to develop diameter growth models for thinned Quercus glauca Thunb. (QGT) stands to inform production goals for treatment and provide the information necessary for the systematic management of this stands. Methods: This study was conducted on QGT stands, of which initial thinning was completed in 2013 to develop a treatment system. To analyze the tree growth and trait response for each thinning treatment, forestry surveys were conducted in 2014 and 2021, and a one-way analysis of variance (ANOVA) was executed. In addition, non-linear least squares regression of the PROC NLIN procedure was used to develop an optimal diameter growth model. Results: Based on growth and trait analyses, the height and height-to-diameter (H/D) ratio were not different according to treatment plot (p > .05). For the diameter of basal height (DBH), the heavy thinning (HT) treatment plot was significantly larger than the control plot (p < .05). As a result of the development of diameter growth models by treatment plot, the mean squared error (MSE) of the Gompertz polymorphic equation (control: 2.2381, light thinning: 0.8478, and heavy thinning: 0.8679) was the lowest in all treatment plots, and the Shapiro-Wilk statistic was found to follow a normal distribution (p > .95), so it was selected as an equation fit for the diameter growth model. Conclusion: The findings of this study provide basic data for the systematic management of Quercus glauca Thunb. stands. It is necessary to construct permanent sample plots (PSP) that consider stand status, location conditions, and climatic environments.

• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.169-178
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• 2020

This study aimed to compare the organic carbon stocks of Cryptomeria japonica and Chamaecyparis obtusa stands established under a similar-site environmental condition in South Korea. C. japonica and C. obtusa stands adjacent to each other from 13 representative regions were chosen to evaluate the carbon stocks of tree biomass, forest floor, and mineral soils. Mean stand ages were 45 years for C. japonica and 43 years for C. obtusa, respectively. Tree density was significantly lower in C. japonica (989 tree ha^-1) than in C. obtusa (1,223 tree ha^-1) stands, whereas diameter at breast height and dominant tree height values were significantly higher in C. japonica (27.4 cm and 20.4 m, respectively), compared with C. obtusa (23.9 cm and 17.9 m, respectively) stands. The total carbon stocks of tree biomass were linearly related with stand basal area (C. japonica: r² = 0.82; C. obtusa: r²= 0.92; P< 0.05), whereas stand density and site index were not correlated with the carbon stocks of tree biomass (P > 0.05). The carbon stocks of aboveground tree biomass were significantly higher in C. obtusa (117.7 Mg C ha^-1), compared with C. japonica (95.5 Mg C ha^-1) stands, whereas carbon concentration and stocks of the forest floor and mineral soil layers were insignificantly different between the C. japonica and C. obtusa stands. The results indicated that trees in C. obtusa stands sequestrated more carbon dioxide, compared with C. japonica stands, whereas carbon stocks in the forest floor and mineral soil layers were unaffected by stand development processes of the different tree species.

• Journal of Korean Society of Forest Science
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• v.95 no.6
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• pp.729-734
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• 2006

This paper aimed to suggest decision-making method for forest management planning using integer programming. Thus, the study examined 85 stands consisting of Korean pine, Japanese larch and oak stands-all of which were at the most suitable time for tending, selection thinning, commercial thinning and final cutting-in the experimental forest of Kangwon National University. The forest management model comprised one objective function, maximizing harvest volume in each stand according to tree species and the kinds of practices, and seven constraints: frequency and stands of practices, minimum and maximum yields, even yields, maximum production, and decision-making varialbes. Besides, the entire period intended by the study was 10 years, divided into 5 management periods. In conclusion, the forest management planning model using integer programming proved that among 85 stands, forest practices were conducted over 68 stands (202.8 ha), producing the total harveted volume of $20,000m^3$, while the rest was reserved. This case study could help make decisions on whether and when the forest practices and harvests could be done in a specific condition.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.2
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• pp.65-71
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• 2002

The best environments such as crown density, temperature, light intensity and humidity have to be identified because these factors are strongly related to the growth and several physiological characteristics. The purposes of this study are \circled1 to collect basic data fer growth, \circled2 to identify the best growth environments. to achieve these purposes, oak, pine and mixed forest stands have been selected in this study. forest ginseng seeds were sown in these forest four years ago. Several environmental and growth factors have been surveyed. In general, mean tree age, DBH and average height are 20-25 years old, 14-17 cm and 7-9 m, respectively. The growths of forest ginseng grown in oak stand are better than those of pine and mixed stands.

• Journal of Forest and Environmental Science
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• v.34 no.2
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• pp.119-125
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• 2018

The tropical forests in developing countries are faced with the problem of illegal exploitation of trees. However, dearth of empirical means of expressing the dimensions, structure, quality and quantity of a removed tree has imped conviction of offenders. This study aimed at developing a model that can effectively estimate individual tree basal area (BA) from stump diameter (Ds) for Tectona grandis stands in Omo Forest Reserve, Nigeria, for timber valuation in case of illegal felling. Thirty-six $25m{\times}25m$ temporary sample plots (TSPs) were laid randomly in six age strata; 26, 23, 22, 16, 14, and 12 years specifically. BA, Ds and diameter at breast height were measured in all living T. grandis trees within the 36 TSPs. Least square method was used to convert the counted stumps into harvested stem cross-sectional areas. Six basal area models were fitted and evaluated. The BA-Ds relationship was best described by power model which gave least values of Root mean square error (0.0048), prediction error sum of squares (0.0325) and Akaike information criterion (-15391) with a high adjusted coefficient of determination (0.921). This study revealed that basal area estimation was realistic even when the only information available was stump diameter. The power model was validated using independent data obtained from additional plots and was found to be appropriate for estimating the basal area of Tectona grandis stands in Omo Forest Reserve, Nigeria.

• Korean Journal of Environmental Biology
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• v.25 no.2
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• pp.158-167
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• 2007

A study conducted in NaeSorak Mt. from 1996 to 2006 shows some interesting results indicating general characteristics of natural forests, regeneration and structural patterns on fir stands. Those fir stands could have been confused as climax forests, which is a short-sighted from human-centered view on those stands. A classic theory of succession, which has been frequently applied to analyse the changes in forest ecosystem changes, failed to provide further understanding of fir stands. To comprehend the complicated and diverse process, a concept of ecosystem circulation need be introduced to the theory. This is a main idea of 'patch dynamics' theory developed from 'mosaic cycle' theory.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.160-166
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• 2009

We estimated site productivity for unstocked land based on the relationship between site index (i.e., average height of dominant trees at fixed age) and soil physico-chemical properties of Pinus densiflora stands. Site index relates to a direct method of determining a tree's response to a specific environment such as forest soil and climate conditions. We selected 78 sites in 22 P. densiflora stands of central temperate forest zone, and sampled soils for physicochemical analyzing. And 13 properties of soils were statistically treated by stepwise regression. In the degree of contribution of the variables to site index, the highly effective variables in A horizon were OM, clay content, sand content, available $P_2O_5$, and Exch. $Ca^{{+}{+}}$ inorder, and in B horizon T.N., O.M., Soil pH, cation exchange capacity(C.E.C.), and sand content in order. In both A and B horizon of the soil for P. densiflora stands, the variables commonly contributed to the site index were sand content and OM. These results may be useful to provide not only important criteria for establishment of Pinus densiflora stand sespecially in unstocked land but also aguidance for reforestation.