• Journal of Forest and Environmental Science
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• v.31 no.1
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• pp.47-54
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• 2015

The study was performed to analyze the growth of the red pine (Pinus densiflora) in the Eastern Region of Korea. Stem profile data from a total of 8 dominant trees of which each tree represents its site were collected and used for the analysis. The stem volumes were calculated using Smalian's formula and much higher than the ones by Korea Forest Research Institute in larger than dbh 40 cm. The total bark volumes were more proportionally related to dbh and stem volume than to height and age. The bark thickness and volume decreased as relative height increases but increased as relative dbh increased. The average PAI of dbh and height reached the highest at 0.8 cm/yr (age 15) and at 0.45 m/yr (age 30) respectively, while the average PAI of volume steadily tended to increase up to age 80. The growth percentages of dbh, height and volume tended to decrease with age and volume growth percentage was higher than dbh and height.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.539-551
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• 1996

In this study, a number of distance-dependent competition indices on tree-level which incorporate the tree sizes and distances to competitors, and traditional stand-level density measures were estimated from the data compiled with position-dependent survey in a Pinus densiflora stand. The performance of the estimated competition indices was examined by comparing the relationship with the diameter growth, and a dbh growth function, in which the competition index is considered as a one of influence factors, are developed. In the searching method of competing trees, the competition index estimated with $30^{\circ}$ competition interrupting angle showed the highest correlation with the annual dbh growth, while the expanding the competing zone distance had no significant effect on the performance of competition index in estimating annual dbh growth. The most of the examined stand-level competition indices, based on distance-dependent single-tree competition indices, were evaluated to describe similarly the stand competition status. As a result of partial correlation analysis in which the effect of age and site index are eliminated, Alemdag's mean competition index and relative spacing index were determined to have the highest correlation with dbh. The relative spacing index, which can be easily measured in field without measuring the position of individual trees, was considered to be a better suited one for estimating mean dbh of a stand. Among distance-dependent competition indices on tree-level, Hegyi's competition index showed the best performance in their correlation with annual dbh growth, if eliminated the effect of site index and dbh. This enabled to derive the following annual dbh growth function of individual trees which incorporate age, dominant height, dbh and Hegyi's competition index as influence factors : $$dbh^{\prime}=3.975362676{\cdot}age^{-1.099274613}{\cdot}ho^{0.199893990}{\cdot}dbh^{0.269430865}{\cdot}HgCI^{-0.353643587}$$ This function is coincided to the growth principle in which site index has a positive effect on the annual dbh growth, while high age or competition causes to reduce the annual dbh growth, and can be used as a function in single tree growth model.

• Journal of Forest and Environmental Science
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• v.34 no.3
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• pp.235-241
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• 2018

This study was conducted to find out the growth pattern of Pinus koraiensis plantation over 34 years, focusing on DBH, height, basal area and allometric change. Total increment (TI), mean annual increment (MAI) and correlation coefficient were calculated and compared with stand and dominants. Total increment and mean annual increment of both DBH and height of dominants were bigger than those of stand. The difference was apparently shown bigger in DBH than height. Unlike DBH and height the total increment and mean annual increment of basal area per hectare of dominants were distinctively smaller than those of stand. Furthermore MAI of dominant was increasing until age 42, while MAI of stand increased at early ages and then gradually decreased after culmination like MAIs of DBH and height. MAIs of basal area of dead trees at each measurement tended to increase until early age (18 years in this study), while it reached a peak and gradually decrease after that (21 years in this study). Correlation coefficient between DBH and height tended to decrease as both dominant and stand age and the difference between dominant and stand was not clearly shown over the measurement period. Correlation coefficients between DBH and crown width tended to decrease as the trees age and correlation coefficients of dominant were clearly shown smaller than that of stand. Correlation coefficients of height and crown width also was found to be similar to correlation coefficients between DBH and crown. Meanwhile correlation coefficient of height and crown width dropped more radically than coefficient of DBH and crown width as the trees age.

• Journal of Korean Society of Forest Science
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• v.96 no.2
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• pp.189-196
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• 2007

Allometry, basal area equations, and volume equations were developed with various tree measurement variables for the major species, Quercus mongolica and Quercus variabilis, in Korean natural hardwood forests. For allometry models, the relationships between total height-DBH, crown width-DBH, height to the widest portion of the crown-total height, and height to base of crown-total height were investigated. Multiple regression methods were used to relate annual basal area growth to tree variables of initial size (DBH, total height, crown width) and relative size (relative diameter, relative height) as well as competition measures (competition index, crown class, exposed crown area, percent exposed crown area, live crown ratio). For tree volume equations, the combined-variable and Schumacher models were fitted with DBH, total height and crown width for both species.

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

• The Korean Journal of Ecology
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• v.26 no.4
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• pp.155-163
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• 2003

In order to analyze the succession process from a pine forest to an oak forest, the tree growth of Pinus densiflora and Quercus mongolica ssp. crispula was monitored in a permanent quadrat for 23 years. The measurements were carried out for the stem diameter (DBH) of Pinus densiflora between 1977 and 1999 and for the height of Quercus mongolica ssp. crispula saplings between 1998 and 2000. The floristic composition and the locations of the individual P. densiflora and Q. mongolica ssp. crispula trees and saplings in the quadrat were recorded. P densiflora and Q. mongolica ssp. crispula individuals were randomly distributed within the quadrat. The relative growth rates (RGR) of DBH in P. densiflora were 0.085 $yr^{-1}$ for large trees and 0.056 $yr^{-1}$ for small trees in 1977. The RGR of height for Q. mongolica ssp. crispula was 0.122 $yr^{-1}$. The growth curve for DBH of P. densiflora was approximated by the logistic equation: $$DBH(t) = 30 {[1+1.16exp(-0.13 t)]}^{-1}$$ where DBH (t) the DBH (cm) in year t and t is the number of years since 1977. The growth in height of P. densiflora and Q. mongolica ssp. crispula was described by following equations: $$H (t) = 20.2 {[1+0.407exp(-0.137 t)]}^{-1} (P. densiflora)$$ $$H (t) = 30 {[1+20.7exp(-0.122 t)}^{-1} (Q. mongolica ssp. crispula)$$ Where H (t) is the tree height (m) in year t and t is the number of years since 1977 in P. densiflora and 1998 in Q. mongolica ssp. crispula. With these equations we predicted that the height of Q. mongolica ssp. crispula increases from 2 m in 1999 to 20 m in 2029. Therefore, Q. mongolica ssp. crispula and P. densiflora will be approximately the same height in 2029. The years required for succession from a pine forest to an oak forest are expected 33 with the range between 23 and 44 years.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.266-278
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• 2012

The objective of this study was developing dynamic stand growth model to predict diameter at breast height (DBH) growth by thinning intensity and cycle for major tree species of South Korea. The yield table, one of static stand growth models, constructed by Korea Forest Service was employed to prepare dynamic stand growth models for 8 tree species. In the process of model development, the thinning type was designated to thinning from below and equations for predicting the DBH change after thinning by different intensities was generated. In addition, stand density (N/ha), age and site index were adopted as explanatory variables for DBH prediction model. Thereafter, using the model, DBH growth under various silvicuture through integrating such equations considering thinning intensities, and cycles. The dynamic stand growth model of DBH developed in this study can provide understanding of effectiveness in forest growth and growing stock when thinning practice is performed in forest. Furthermore, results of this study is also applicable to quantitatively assess the carbon storage sequestration capability.

• Journal of Forest and Environmental Science
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• v.31 no.4
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• pp.255-260
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• 2015

Height growth models for Pinus thunbergii in Jeju Island were developed in this study using four widely used nonlinear growth models; Exponential, Modified Logistic, Chapman-Richards, and Weibull. All functions were found to be significant at the 1% level. Chapman-Richards model for height-DBH allometry and Weibull model for height-age allometry was chosen as the best model on the all validation. All the model curves showed the similar pattern. Additionally, there was no abnormal pattern when the previous studies were compared. Therefore, these models are highly expected to be used to estimate the tree height using DBH or age for Pinus thunbergii especially in Jeju Island.

• Journal of Forest and Environmental Science
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• v.27 no.1
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• pp.47-54
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• 2011

Allometry and basal area equations were developed with various tree measurement variables for the major species; Quercus variabilis, Quercus mongolica, Pinus koraiensis and Larix leptolepis in Korea. For allometry models, the relationships between total height-DBH, crown width-DBH, height to the widest portion of the crown-total height, and height to base of crown-total height were investigated. Multiple regression methods were used to relate annual basal area growth to tree variables of initial size (DBH, total height, and crown width), relative size (relative diameter and relative height) as well as competition measures (competition index, crown class, and live crown ratio).

• Korean Journal of Environment and Ecology
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• v.32 no.2
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• pp.215-224
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• 2018

The climate change is expected to weaken the habitat of Pinus densiflora and P. thunbergii, but they are still in high demand for planting. This study aims to suggest the rational community planting design based on natural forests' community structure in the southeastern region of Korea (warm temperate zone). For this study, we surveyed 22 plots of Pinus densiflora community and 60 plots of P. thunbergii community in Busan Metropolitan City which is located in the southeastern part of the Korean peninsula. We investigated the diameter of breath hight (DBH) and population of each tree layer in a $100m^2$ quadrat and used a regression analysis to derive a regression equation for estimating the mean number of planting individuals in each DBH. The coefficient between canopy layer's DBH and growth individuals per unit area ($100m^2$) was 0.700 for P. thunbergii communities and 0.533 for P. densiflora communities, indicating very high explanatory power by single factor. The predicted regression equation of between DBH and growth density was $Y=31.176e^{-0.055x}$ (X=DBH, Υ=growth individuals per $100m^2$) for P. thunbergii communities and $Y=38.351e^{-0.059x}$ for P. densiflora communities. Planting densities of P. densiflora communities and P. thunbergii communities in southeast region were higher than the central region.