• Journal of Forest and Environmental Science
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• v.36 no.1
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• pp.17-24
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• 2020

This study aimed to figure out and compare the increment of biomass by thinning intensity focused on the plantation of the two major coniferous species (Larix kaempferi and Pinus koraiensis) of South Korea. The inventory interval was three years under the effects of three types of thinning treatments; control (no thinning), light (20% thinning) and heavy (40% thinning). The results showed standing biomass increment of both species decreased as thinning intensity increased (heavylight>control). Meanwhile, the lowest of on-site biomass changes occurred in the control plot, and the greatest was in the heavy thinning plot because thinning was involved with leaving the felling residual biomass (leaves, branches and roots) on the site. According to the results from this short-term study, unthinned stands is preferable for maximizing standing biomass as well as carbon sequestration. However long-term investigation should be considered in order to see more clear results.

• Journal of Ecology and Environment
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• v.46 no.1
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• pp.85-98
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• 2022

Background: Korean white pine (Pinus koraiensis) is a major commercial species, and the importance of the oak trees (Quercus spp.) is increasing due to various factors such as environmental and ecological values. However, more information is required to clearly understand the growth characteristics of these species especially regarding thinning intensity. This study was performed to provide the basic information to develop the silvicultural guideline and field manual by analyzing tree and stand characteristics in line with thinning intensity in the Korean white pine plantation and oak-dominated natural deciduous forest. Results: Diameter at breast height (DBH) and volume changes by the thinning intensity in the Korean white pine plantation were significantly different from those in the oak-dominated deciduous natural forest. In particular, DBH distribution in the pine stand appeared that there were more large diameter trees as the thinning intensity was higher. DBH periodic annual increment (PAI) of the pine stand was higher as the thinning intensity was stronger and the growth period was shorter. This trend was similarly shown in the natural deciduous forest, but the amount of PAI was smaller than in pine stand. The volume PAI after thinning was not decreased over time. In each stand type, the PAI tended to be lower as stand density was higher. The volume PAI in the pine stand was significantly higher than that in the oak-dominated natural deciduous forest. Dead trees occurred the most in the unthinned plots of each stand type, and those were higher in the natural deciduous forest. Ingrowth trees were observed only in the natural deciduous forest, and its distribution was the lowest in unthinned plots; Korean white pine as ingrowth occurred the most frequently among many tree species. Conclusions: Different effects of thinning treatment on DBH and volume PAI, mortality, and ingrowth were observed for each stand. With respect to forest growth, Korean white pine plantation was superior to the oak-dominated natural deciduous forest. The results of this study offer fundamental information for the development of silvicultural guidelines for Korean white pine plantations and oak-dominated natural deciduous forests in Korea.

• Journal of Korean Society of Forest Science
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• v.99 no.2
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• pp.186-196
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• 2010

Fertilization increases the crop productivity and produces high quality seedlings for plantation. We quantitatively measured both physical performances and nutrient responses of Fraxinus rhynchophylla, Fraxinus mandshurica, Pinus koraiensis, and Abies holophylla seedlings, which are commercially planted species in Korea, to nitrogen, phosphorus, and potassium fertilization. We analyzed the growth performances by using Dickson's quality index (QI) and the nutrient status by using vector diagnosis. Nitrogen or phosphorus treatment increased height and root collar diameter growth of F. rhynchophylla and F. mandshurica, however, did not increase those of P. koraiensis and A. holophylla. The order of QI was N > P > K > control for F. rhynchophylla, P ${\geq}$ N > Control ${\geq}$ P for F. mandshurica, P > Control ${\geq}$ K > N for P. koraiensis and A. holophylla. In F. rhynchophylla, fertilization diluted N concentration in tissues by 5-25% because growth responses were higher than fertilization uptake. P. koraiensis and A. holophylla showed N excess showing "toxic accumulation". F. rhynchophylla and F. mandshurica showed P deficiency with P fertilization, however, P. koraiensis and A. holophylla showed "luxury accumulation". Vector diagnosis indicated that more fertilization was applicable for F. rhynchophylla and F. mandshurica, and high fertilization rates were inefficient for P. koraiensis and A. holophylla. Both QI and vector diagnosis can be applied to verify seedling quality in the light of growth responses and nutrient status in fertilization trials.

• Journal of the Korean Wood Science and Technology
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• v.34 no.4
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• pp.66-75
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• 2006

This study was conducted to understand the biomass and the energy content of 24-year-old Pinus koraiensis stand planted in Mt. Wolak, Chungcheongbuk-do, Korea. Nine sample trees were selected and harvested for the study. Stem, bark, branches and leaves were weighed respectively with the stratified clipping method, and analyzed for productive structure. The allometric regression equations between dry weight of each component and $D^2H$ were obtained to estimate the total biomass of aboveground (47.0 ton/ha) and other parts (56.5% from stemwood, 9.1% from stembark, 0.5% from current twigs, 18.4% from live branches, 2.6% from current leaves, and 12.9% from previous leaves). Annual net production of aboveground was 6.0 ton/ha/yr, and the ratios of stemwood, stembark, current twigs, live branches, and current leaves to that of aboveground were 49.8%, 7.3%, 3.5%, 18.6%, and 20.8%, respectively. Energy content of aboveground was 1,028 GJ/ha, and annual energy content was 133 GJ/ha/yr. Leaf area index (LAI) of P. koraiensis plantation was 20.2 in Mt. Wolak.

• The Korean Journal of Ecology
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• v.10 no.1
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• pp.43-51
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• 1987

The forest vegetation of Jongyeoul hill, Seoul, was classified into six secondary forests and two plantations by ZM method; Pinus densiflora, Quercus acutissima, Pinus rigida, Robinia pseudoacacia and Alnus hirsuta-Quercus mongolica community, and Castanea crenata and Pinus koraiensis plantation. In the herb layer the species richness and total coverage of deciduous broad leaf forests showed higher values than those of evergreen needle leaf forests. The peak in July at Q. acutissima forest and in the middle of June at R. pseudoacacia forest. Simpson's diversity index(Ds) in different stands are as follows: Ds>0.6 in R. pseudoacacia forest, Ds=0.3~0.6 in Q. acutissima forest and Ds<0.3 in P. densiflora and P. rigida forest. It is found that, although dominance rank and importance value were originated from different school each other, two measures can be used exchangablym showing almost linear positive correlation between them in this study.

• Journal of Korean Society of Forest Science
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• v.97 no.6
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• pp.597-604
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• 2008

Recognizing the necessity of the development of ecologically sound silvicultural system for the mature Korean pine (Pinus koraiensis), this study was carried out to examine the invasion and growth of understory vegetation after partial cutting. In 1997, the age class VII Korean pine forest in the Experimental Forest of Kangwon National University was opened up about 50% by modified shelterwood cutting with site preparation to induce succeeding regenerations. After 10 years, plenty of hardwood have come to the stand, forming understory vegetation. The abundance and composition of understory vegetation was periodically investigated in the ten $10m{\times}10m$ permanent sample plots, estimating importance values, species diversity index and the distribution of diameter and height of the understory vegetation. Encouraged by canopy opening, the coverage of understory reached perfect closure, composed of 22 tree species and 20 shrub species in 2007. Morus bombycis occupied 29.6% of the total importance value and Cornus controversa was 17.0%, followed by Styrax obassia, Quercus aliena, Quercus mongolica, Acer mono, and Pinus koraiensis. In the year of 2000 the species diversity was highest as 2.547 with 26 tree species and deceasing thereafter, showing 2.220 with 22 tree species in 2007. As understory layer was thickly covered and got grow bigger, some shade intolerant species were disappeared, lowering species diversity. In 2007 the biggest tree was a Quercus aliena with 11.3 cm of DBH and the tallest tree was a Cornus controversa with 9.8m of height. The frequency distribution of number of trees by diameter and height classes formed the inverted-J-shaped curve, supposed to be typical uneven-aged stand.

• Journal of Forest and Environmental Science
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• v.13 no.1
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• pp.66-80
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• 1997

Pinus koraiensis is one of the major speciese which have been recently planted for ten years and consists of 31% of total plantation. Presently young stand less than 30 years consists of 87% of total forest, but tending thinning of it is hardly carried out and the desirable direction for the thinning is not established yet. The objective of the study is to introduce the optimum thinning plan and thinning method through the long-run experiment of tending thinning for the Pinus koraiensis stand. The experiments carry out to interprete its growth model on the subject of two thinning experimental plots and yield table of Pinus koraiensis. As the basic step for understanding the thinning process, a theoretical growth model which is suitable to express the growth process is required. For that purpose, three growth functions (Mitscherlich, 4 parameter Richards, 3 parameter Richards) are applied to the diameter growth of the sample trees which are taken in the two plots. The results show that 3 parameter Richards is the most suitable. It is also verified that the diameter growth, the height growth, and the decrease in the number of stocks can be estimated by this function. To estimate the growth change of single tree, growth model including parameter h which is related to the occupation area of single tree are introduced. The parameter h can be estimated by using the data of the diameter growth obtained from the established experimental plots. Therefore, if both verification and modification of the usefulness of the model suggested is made, equations which tell about the thinning effects could be drived by estimating the growth process of single tree in advance.

• Journal of Forest and Environmental Science
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• v.33 no.1
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• pp.74-77
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• 2017

The purpose of this study is to analyze the effect of thinning intensity on the growth of large diameter trees in Korean white pine (Pinus koraiensis S. et Z.) plantation. Eight thinning plots were analyzed by categorizing into heavy thinning, light thinning, no thinning (control) according to thinning intensity. As a result, average DBH increased more in heavy thinning plots than in light thinning or unthinned plots. The number of large trees (DBH>25 cm) were obviously shown the most in heavy thinning plots. It is considered that heavy thinning is needed for the production of the large diameter trees.

• 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 the Korean Wood Science and Technology
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• v.25 no.2
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• pp.117-126
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• 1997

In fast grown softwood, there are very large changes in material properties going outward from the pith to bark such as anatomical, physical and mechanical characteristics. Some of variations in anatomical properties with annual ring were then examined from Pinus koraiensis, Larix leptolepis, and Chamaecyparis obtusa, which are major softwoods of plantation in Korea. The large variations of annual ring width during young age of tree tended to stabilize after 25year through the transitional period in 17~23year. The ring density was 1.5~2.4 in 1~10year period, and 3.5~6.3 in 30~35year period, in which juvenile and mature wood were certainly assumed to be formed, respectively. Variations of tracheid length showed functional relationships with annual rings as logarithm. Demarcation between juvenile wood and mature wood could be 16~19year, which was determined from increase rate of tracheid length of 0.2%. Cell wall thickness increased with increase of annual ring even though large variations were observed as well. Variations of cell wall thickness within species were pronounced in latewood than earlywood. The increase of cell wall thickness from juvenile wood to mature wood was predominant in Larix leptolepis as 2.0times, and least in Chamaecyparis obtusa as 1.1 times. Cell diameters showed trends of increase during young age of 1~15year, and consistent afterward. The variations of cell diameter between radial and tangential direction were greater in latewood, and most pronounced in Chamaecyparis obtusa.