• The Korean Journal of Quaternary Research
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• v.18 no.2 s.23
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• pp.107-107
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• 2004

In this paper we have introduced some results of study on stand growth pattern and stand structure of larch forest which are located in selected forest sites of Khangai and Gobi-Altai mountain ranges of Mongolia. Our investigations showed that growth intensity and stand structure in western Mongolia are very specific from the other forest vegetation zones of Mongolia. Studies on the stand structure and growth trend indicate that tree types of stand structure and different types of growth of Larix sibrica are very common in Western Mongolia. These peculiarities of stand structure and growth of larch stands in Western Monolia could be used for inventory work and an improvement of the forest management in Western Mongolian region. The larch tree is the dominant tree species in Western Mogolia. Forest cover of the region is about 15%, which is two times higher than the country's average. In this region forest area is divided into 4 forest sub-regions: the Central Khangai, Western Khangai, North Eastern Khangai and South Easterun Khangai sub-regions including taiga, pseudo taiga, sub taiga, sub-alpine and forest steppe belts. Silviculture practices and forest research management request to study forest growth trends in local and general conditions, which means to indicate a change of taxonomic characteristics of stand from time to time including diameter, height, basal area, growth stock etc. The forest management practice mostly uses tables of forest growth and yield based on the results of long term research on forest growth. Forest yield tables and other relevant forest standards of Russia are used for the forest inventory and forest management. They are not able to determine forest structure and growth peculiatities of Mongolian forests. Studies on forest resource assessment in Mongolia indicate that after logging operations and forest fires the natural regeneration of desired species such as pine and larch often does not succeed. This situation forces to take a different approach of forest management and silviculture practice depending on the stand structure and growth rate of the forest stands. According to our investigation in last years, forest growth pattern of larch forest depends mostly on stand structure, stand age and growth condition including forest soil, climate and location in different slopes. Due to improve environmental function of forest ecosystem in the region, it is needed to conduct very comprehensive study of high mountain forest ecosystem in selected sub-regions.

• Journal of Korean Society of Forest Science
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• v.96 no.2
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• pp.145-150
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• 2007

This study was conducted to elucidate the mid-growth of Norway spruce at the age of 27 and select the superior provenances in Korea. Growth performance of twenty-four provenances from Germany and Rumania were investigated in four plantations. Significant differences were found in growth (height, DBH, volume) with plantations. Maximum growth were detected on plantation Chuncheon which located in most northern area, and minimum growth were detected on plantation Wanju located in most southern area. The rank of height in provenances has fluctuated, but superior/inferior groups have been almost fixed. 840-23, 840-10, 840-19 in Germany, G1-64-57, G1-64-54 in Rumania proved excellent provenances. Height in early stage positively correlated with that in late stage. The growth was positively correlated with latitude and altitude of plantations, but negatively correlated with temperature.

• Korean Journal of Agricultural Science
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• v.51 no.1
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• pp.25-39
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• 2024

This study aimed to determine a method for restoring grasslands to forests in mountainous areas. The study was conducted in an area damaged by trampling due to construction activity and herding. Additionally, there were concerns of hindered tree growth due to the alpine region climate, characterized by the low temperatures, drying, and strong winds. Therefore, forest restoration treatments such as tillage, furrow, and shading were performed to improve growth conditions. From July 2021 to April 2023, soil temperature and moisture were monitored for each treatment plot, and changes in the initial growth and survival rate of Abies holophylla were investigated. Both soil temperature and soil moisture showed significantly higher values during the four seasons in the grassland-furrow treatment plot (p < 0.05). Compared to the grassland-control plot, the average soil temperature in winter was as high as 1.1℃, and the soil moisture in summer was as high as 20.3%. Additionally, the survival rate and relative growth rate were the largest in the grassland-furrow treatment plot. The survival rate was 87.5%, the relative growth rate in terms of height was 0.013, and the relative growth rate in terms of diameter at root collar was 0.023, indicating that furrow treatment had a positive effect on the initial survival and growth of seedlings. These results suggest that furrow treatment may be an appropriate restoration method when implementing forest restoration projects in areas where tree growth is challenged.

• Journal of Korean Society of Forest Science
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• v.98 no.2
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• pp.170-177
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• 2009

There are remarkable differences in growth and morphological characters of roots between mountain and field cultivated Panax ginseng. Growth of root in mountain cultivated ginseng was much slower than that of field cultivated ginseng. However, the factor affecting the retarded growth in mountain ginseng was not known. Soil analysis revealed that phosphorus (P) content of mountain soil was exceptionally low at least ten-fold lower compared to that of field soil. Thus, we suggest that low availability of P in mountain soil may be one of the limiting factors for growth of ginseng in mountain soil environment. We had monitored the growth of ginseng plants after one and three years of phosphate fertilizer application. Three kinds of phosphate fertilizers: fused magnesium phosphate, fused superphosphate, and single superphosphate were applied to mountain soil. Application of phosphate fertilizers increased the fresh-, dry weight, and diameter of ginseng roots and resulted in increased P accumulation in roots. These results demonstrate that slow growth of ginseng in mountain soil environment might be attributed to the low P content in mountain soil. Thus, analysis of P amount in mountain soil will be a good indicator for the selection of suitable site the ginseng cultivation in forest.

• Journal of Forest and Environmental Science
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• v.39 no.4
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• pp.195-202
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• 2023

In this study, we sought to compare and evaluate the accuracy and predictive performance of machine learning algorithms for estimating the growth of individual Larix kaempferi trees in Gangwon Province, Korea. We employed linear regression, random forest, XGBoost, and LightGBM algorithms to predict tree growth using monitoring data organized based on different thinning intensities. Furthermore, we compared and evaluated the goodness-of-fit of these models using metrics such as the coefficient of determination (R²), mean absolute error (MAE), and root mean square error (RMSE). The results revealed that XGBoost provided the highest goodness-of-fit, with an R² value of 0.62 across all thinning intensities, while also yielding the lowest values for MAE and RMSE, thereby indicating the best model fit. When predicting the growth volume of individual trees after 3 years using the XGBoost model, the agreement was exceptionally high, reaching approximately 97% for all stand sites in accordance with the different thinning intensities. Notably, in non-thinned plots, the predicted volumes were approximately 2.1 m³ lower than the actual volumes; however, the agreement remained highly accurate at approximately 99.5%. These findings will contribute to the development of growth prediction models for individual trees using machine learning algorithms.

• Journal of Korean Society of Forest Science
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• v.94 no.2 s.159
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• pp.73-81
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• 2005

This study was conducted to examine the geographic variation among provenances of Pinus densiflora in survival rate and height growth at four test plantations (Jungsun, Chungju, Naju, and Jeju). The plantations were parts of the eleven provenance trials of Pinus densiflora established by Korea Forest Research Institute in 1996. The survival rate and height growth were significantly different among test plantations at $p{\leq}0.01$. Latitude and longitude of test plantation were negatively correlated with survival rate and height growth. On the other hand, annual mean temperature, mean temperature (Nov.~Feb.), extremely low temperature (Dec.~Feb.), and annual mean growing days of test plantation were positively correlated with these two. The relationships between growth variables and geographic variables were analysed with canonical correlation analysis. A considerable amount of variation in survival rate and height growth was explained by latitude, annual mean growing days, extremely low temperature (Dec.~Feb.) and extremely high temperature (Nov.~Feb.) of provenances. It is estimated that up to 47.1% and 67.4% of the genetic variability in survival rate and height growth was attributable to the environmental variability of the provenances, respectively. The response surface curve of survival rate and height growth was plotted against latitude and longitude to examine growth performance of provenances for each test site. Generally, the local provenances showed better survival rate and height growth.

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.377-386
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• 2008

The growth performance of Eastern white pine (Pinus storbus L.) was studied with six provenances in four plantations. All growth performances were significantly different among provenances and plantations. The most outstanding source in volume growth at age 39 is North Carolina in all plantations and this trends had been started from four years old seedlings. In plantations, the growth is best in ChunCheon plantation while that is worst in GunPo plantation. The Effect of plantations was thought to be larger than that of provenances growth of P. strobus. A pattern of growth by ages was different by among plantations and even ate age about 40, the growth was still vigorous. Annual precipitation, foggy days, altitude and sand contents in soil are positively correlated with growth and the correlations between by ages were very high.

• 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 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 Forest and Environmental Science
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• v.27 no.3
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• pp.157-167
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• 2011

This study was conducted to analyze the stand structure and growth characteristics along different elevations of Pinus koraiensis natural forests located at mean elevation 1,300 m (site1), 900 m (site2) and 600 m (site3) on Mt. Seorak. Mean DBH and height of P. koraiensis were 25.4 cm and 12.3 m in site1, while that of site2 and 3 were over 40 cm and 20 m, respectively. For this reason, there was 5 times difference of single tree volume between site1 and other sites(p<0.05). Mean ringwidth increment of P. koraiensis was 1.1 mm/yr in site1, 1.5 mm/yr in site2 and 2.6 mm/yr in site3. However, recent growth of ringwidth has increased by 8.6% in site1, whereas site2 and 3 have fallen by approximately 50% over the last 10 years. These results signify that the growth and distribution of natural P. koraiensis are effected by different climatic environment along elevations.