• Journal of Korean Society of Forest Science
• /
• v.101 no.4
• /
• pp.599-605
• /
• 2012

The purpose of this study is to estimate diameter distribution, volume per hectare, and carbon stock for Quercus variabilis stand. 354 Quercus variabilis stands were selected on the basis of age and structure, the data and samples for these stands are collected. For the prediction of diameter distribution, Weibull model was applied and for the estimation of the parameters, a simplified method-of-moments was applied. To verify the accuracy of estimates, models were developed using 80% of the total data and validation was done on the remaining 20%. For the verification of the model, the fitness index, the root mean square error, and Kolmogorov-Smirnov statistics were used. The fitness index of the site index, height, and volume equation estimated from verification procedure were 0.967, 0.727, and 0.988 respectively and the root mean square error were 2.763, 1.817, and 0.007 respectively. The Kolmogorov-Smirnov test applied to Weibull function resulted in 75%. From the models developed in this research, the estimated volume and above-ground carbon stock were derived as $188.69m^3/ha$, 90.30 tC/ha when site index and stem number of 50-years-old Quercus variabilis stand show 14 and 697 respectively. The results obtained from this study may provide useful information about the growth of broad-leaf species and prediction of carbon stock for Quercus variabilis stand.

• Journal of Korean Society of Forest Science
• /
• v.94 no.1 s.158
• /
• pp.45-49
• /
• 2005

Although the forest accounts in Korea have been constructed partly as the research projects since the mid-1990s, the framework of the accounts has not yet been established. The objective of this study is to provide the physical asset accounts of forested land and forest stock based on the system of integrated environmental economic accounts(SEEA) by utilizing the restructured 2004 statistical yearbook of forestry in Korea. In 2004 yearbook, new variables such as logging area and volumes are added. The logging area and volumes play important roles in constructing forest accounts because the basic structure of the physical asset accounts are composed of the opening stock, closing stock, and the changes between the two. The changes between the opening and closing stock are largely explained by the harvest. In forest accounts, in general, the main elements for the increase in stock are afforestation and reforestation while the main cause for the decrease is logging. In this study we separate the logging into natural or man-made causes. In addition, other useful information for the status of forest is recorded in an annex even if it is not necessary element in the account table. According to the forested land asset accounts generated with 2003 data, the logging area is larger than the reforestation area, and the total forested land is decreased. The logging volume is 0.4% of the total stock volume, and the planed logging volume is more than 3 times larger than the damaged logging volume. The damaged logging volumes by man-made causes is about $300,000m^3$, and it is much than that of natural causes, which is about $55,000m^3$.

• Journal of Forest and Environmental Science
• /
• v.30 no.1
• /
• pp.101-106
• /
• 2014

The purpose of this research was to figure out the stand structure and growth characteristic with relation to DBH, height, and volume in sixteen Pinus koraiensis plantations of Gangwon province region. Age class was diversely distributed from age class II (16 yr) to age class VIII (77 yr), and, in terms of site index, sixteen regions were superior: nine regions 'high', seven regions 'middle'. The distribution of DBH by sites appeared a bell-shaped curve, and the number of trees was the most in diameter section of 18-22 cm. The dispersion of DBH was various with age and widest ranging from 18 cm to 58 cm in age class VII-VIII. The distribution of height was also a bell-shaped curve with the smaller deviation than the distribution of DBH, and most of trees were in height section of 14-18 m. The correlation of DBH and height was high (r=0.75), and the volume bigger than 1.0 $m^3$ was presented from DBH 35 cm, height 20 m.

• Journal of Korean Society of Forest Science
• /
• v.106 no.3
• /
• pp.300-309
• /
• 2017

The productivity, cost, and optimal forest road network density for tree-length yarding with K301-4 and HAM300 tower yarders were analyzed. The results showed that productivity decreased as the yarding distance increased. The productivity of the K301-4 was greater than that of the HAM300 as the maximum yarding distance was longer than 34 m. This difference increased as the load volume increased. As the K301-4 yarder had a higher purchase price and it took more time to set up compared to the HAM300, the HAM300 was cost effective. Therefore, in oder to introduce tower yarders to reduce operational cost, it is effective to increase the load volume during operations and to utilize the road network repeatedly for a long period.

• Journal of Forest and Environmental Science
• /
• v.30 no.3
• /
• pp.259-266
• /
• 2014

Stand Density Diagrams (SDD) are average stand-level models which graphically illustrate the relationship between yield, density and mortality throughout the various stages of forest development. These are useful tools for designing, displaying and evaluating alternative density regimes in even-aged forest ecosystems to achieve a desired future condition. This contribution presents an example of a SDD that has been constructed for teak forests of Karnataka in southern India. The relationship between stand density, dominant height, quadratic mean diameter, relative spacing and stand volume is represented in one graph. The relative spacing index was used to characterize the population density. Two equations were fitted simultaneously to the data collected from 27 sample plots measured annually for three years: one relates quadratic mean diameter with stand density and dominant height while the other relates total stand volume with quadratic mean diameter, stand density and dominant height.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.20 no.3
• /
• pp.181-194
• /
• 2017

This study aims to develop a regression model for forest volume estimation using field-collected forest inventory information and airborne LiDAR data. The response variable of the model is forest stem volume, was measured by random sampling from each individual plot of the 30 circular sample plots collected in Bonghwa-gun, Gyeong sangbuk-do, while the predictor variables for the model are Height Percentiles(HP) and Height Bin(HB), which are metrics extracted from raw LiDAR data. In order to find the most appropriate model, the candidate models are constructed from simple linear regression, quadratic polynomial regression and multiple regression analysis and the cross-validation tests were conducted for verification purposes. As a result, $R^2$ of the multiple regression models of $HB_{5-10}$, $HB_{15-20}$, $HB_{20-25}$, and $HBgt_{25}$ among the estimated models was the highest at 0.509, and the PRESS statistic of the simple linear regression model of $HP_{25}$ was the lowest at 122.352. $HB_{5-10}$, $HB_{15-20}$, $HB_{20-25}$, and $HBgt_{25}-based$ models, thus, are comparatively considered more appropriate for Korean forests with complicated vertical structures.

• Journal of Korean Society of Forest Science
• /
• v.109 no.3
• /
• pp.281-290
• /
• 2020

The purpose of this study was to determine the optimal planting density for Zelokva serrata plantations. The study sites were located in Gyeongsan (GS) and Sunchang (SC), Korea. One-year-old, bare-root seedlings were planted at densities of 3,000; 5,000; 7,000; and 10,000 trees ha^-1 at the end of March 2015. We measured the root collar diameter and height each September from 2015 to 2019, and then calculated the H/D ratio and stem volume. The root collar diameter and height increased with increased planting density, and the stem volume was significantly higher at 10,000 trees ha^-1 than those at the other planting densities. Planting density did not affect the survival rate or H/D ratio. The root collar diameter, height, and stem volume were higher in GS than those in SC five years after planting. This study highlights that early growth performance was improved at increased planting densities at both sites. This study suggests that the initial planting density of 10,000 trees ha^-1 is suitable to improve the early growth performance of Z. serrata plantations, and that the improved growth performance at higher planting densities may be a silvicultural characteristic of Z. serrata.

• Asian Journal of Turfgrass Science
• /
• v.15 no.4
• /
• pp.181-186
• /
• 2001

In this study, we observed air temperature to make clear that land coverage condition and forest form has a certain relationship to air temperature in a day in various green space. And with revolution analysis, interpreted relationship of air temperature distribution in the green space, of land coverage rate and air temperature, of volume of tree and temperature. With this experimental result, propose green plan, taking into consideration lower effect of air temperature. In this result lower zone is formed in forest and water area, higher zone is done in paved surface and barren ground. And arbor＋subarbor area, water area sur-rounded forest and small river is formed relative lower air temperature. In my opinion to promote efficiency lower air temperature area, it is need to make water area surrounded forest, to make forest form lower air temperature 2∼3 layer forest. Lower air temperature effect is in order of arbor, subarbor, shrub and is proportioned increasing of tree.

• Journal of Korean Society of Forest Science
• /
• v.99 no.4
• /
• pp.638-644
• /
• 2010

This study was carried out to establish the informations on the optimum container for production of Larix leptolepsis container seedlings. Height growth of 1-year-old container seedling was highest in 250 mL of container (19.3 cm), and of 2-year-old seedling was in 500 mL (56.9 cm). On the other hand, the highest growth of root-collar diameter was observed in the both 1-year-old and 2-year-old seedlings grown in 500 mL. Dry mass production in both a whole seedling and each organs of 2-year-old seedling was significantly high in the container with larger volume and lower seedling density. According to the analysis using by WinRhizo program, the larger container in volume showed better root morphological traits such as total root length, root projected area, root surface area, root volume and average root diameter. Among the elements for analysis of root morphological traits, the root volume was the highest one affected by container volume. And it was observed that the root volume was 79.5% and 46.8% in 320 mL and 250 mL, respectively, compared to 500 mL.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.28 no.2
• /
• pp.39-48
• /
• 2000

The purpose of this study is to investigate the factors affecting temperature of urban parks to grasp the relationship between the land coverage in open space as well as the forest condition and decreasing city temperature by difference of purposed are. Futhermore, this research interpreted the relationship between wind direction, air temperature, the land coverage of the green space, the number of tree, green volume, height of tree and the mitigation of city temperature with the revolution analysis. The result of this study is that cool air in open space move leeward and decreasing city temperature is influenced by the difference of the land coverage in open space. Specifically, in order of the arbo $r_{-a}$rbor in the forest zone, the increase of the number of trees was related with temperature surrounding significantly. This study found that the use possibility of the green volume was recognized as the index of the green volume relative to air temperature surrounding. Green space of the city control area is more effective decreasing temperature than that of housing zone.