• Journal of Korean Society of Forest Science
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• v.100 no.1
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• pp.62-69
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• 2011

Six commonly used non-linear growth functions were fitted to individual tree height-dbh data of eight major tree species measured by the $5^{th}$ National Forest Inventory in Chungcheong province. A total of 2,681 trees were collected from permanent sample plots across Chungcheong province. The available data for each species were randomly splitted into two sets: the majority (90%) was used to estimate model parameters and the remaining data (10%) were reserved to validate the models. The performance of the models was compared and evaluated by $R^2$, RMSE, mean difference (MD), absolute mean difference (AMD) and mean difference(MD) for diameter classes. The combined data (100%) were used for final model fitting. The results showed that these six sigmoidal models were able to capture the height-diameter relationships and fit the data equally well, but produced different asymptote estimates. Sigmoidal growth models such as Chapman-Richards, Weibull functions provided the most satisfactory height predictions. The effect of model performance on stem volume estimation was also investigated. Tree volumes of different species were computed by the Forest Resources Evaluation and Prediction Program using observed range of diameter and the predicted tree total height from the six models. For trees with diameter less than 30 cm, the six height-dbh models produced very similar results for all species, while more differentiation among the models was observed for large-sized trees.

• Journal of Korean Society of Forest Science
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• v.111 no.2
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• pp.242-250
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• 2022

Here we aimed to date the year and season of the resin collection from Korean red pines at Worak mountain and investigate the natural healing ability of the wounds using the tree-ring analysis technique. We determined the dating of the resin collection based on the synchronization between the ring-width time series from the wound surface of the experimental trees and the local master chronology, which is the mean time series from the sound surface on the opposite side of the wounds. For the dating of resin collection, we selected thirteen Korean red pines with resin wounds. For the investigation on the annual healing ability of the wounds, we sampled three dead trees out of 13 trees as disks. Through the comparison of the individual ring-width time series from the wounds with the local master chronology, it was verified that the resin collection was undertaken between the spring of 1962 and the autumn of 1975. The mean healing length of the wounds was 15.8 cm over the preceding 42 years, making their annual mean healing 0.38 cm. Through our study we successfully verified the healing ability of the wounded Korean red pines for the resin collection as well as the undocumented resin collection history.

• The Plant Pathology Journal
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• v.15 no.4
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• pp.210-216
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• 1999

TREGRO, a computer simulation model of individual tree growth, was applied to estimate ozone ($\textrm{O}_3$) effects on aspen(Populus tremuloides) growth under ambient and 1.7 times ambient $\textrm{O}_3$ of Seoul in 1996. The three highest $\textrm{O}_3$ (Kuui-dong, Ssangmun-dong, Sungsoo-dong) and the two lowest $\textrm{O}_3$ sites (Mapo-dong, Namgajwa-dong) were evaluated. The current ambient $\textrm{O}_3$ did not affect aspen growth compared to simulation without $\textrm{O}_3$. The only effect was 6.6 percent of total assimilated carbonloss at Ssangmun-dong where the level of $\textrm{O}_3$ was greatest among the 21 sites examined. Decrease as much as 50 percent of total carbon gain was calculated at 1.7 times ambient $\textrm{O}_3$ of the three highest sites. The carbon loss by $\textrm{O}_3$ came from biomass of tissues and total nonstructural cabron (TNC) such as starch and sugar. The most sensitive fraction was TNC and the next was root biomass. Foliage mass was not affected by $\textrm{O}_3$. Structural biomass loss was at best 1 to 3 percent at 1.7 times ambient $\textrm{O}_3$ at the two lowest sites. The daily carbon simulation was affected by $\textrm{O}_3$ mainly during Growth Period 4 (Jul. 21-Oct. 26). Correlations between site, dose, and the simulated responses of aspen (tissue biomass, TNC, respiration, and senescence) ranged from -0.703 to -0.973 depending on the plant responses. The ozone effects on poplar in Seoul are not severe currently, but are probably measurable at Ssangmun-dong. However, severe $\textrm{O}_3$ effects on biomass would occur if $\textrm{O}_3$ levels increase to 1.7 times ambient $\textrm{O}_3$ in Seoul. In addition, v could weaken the trees thus increasing susceptibility to pathogens or insects.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.4
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• pp.66-73
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• 2002

This landscape design proposal was presented to a design competition for the New Government Buildings of Dalseong-gun which was held by the municipal authority of Dalseong-gun in June, 2002. The site is located at 1313 Gumpo-ri, Nongong-eup, Dalseong-gun, Daegu Metropolitan City and has an area of 50,000$m^2$. The judging criteria for the landscape design set by the Dalseong-gun could be articulated as follows : an environmentally friendly design which respects the surrounding n a locale which functions as a community center of Dalseong-gun, a resting place for the welfare of its employees and visitors, and finally a place with diverse landscape elements reflecting the individual identity of each facility. The main design concepts of this project could be summarized as follows : an environmentally friendly design which respects and utilizes the existing natural landscape resources, a design which features a harmony of nature with architecture and exterior space with interior space, and a design which balances esthetic form and practical function. This design consists of four major outdoor spaces ; the lawn, the entry plaza, a pine grove, and a deck area on the third floor. The multi-purpose lawn area near the main entrance area can be used for flea markets, outdoor weddings, and picnics for its neighbors. The adjacent plaza and parking lots can be unified as one space in case of large events. The entry plaza has three axes. Each of them represents the Assembly, the Administration, and the Culture. A big circle in the paving pattern unifies the three individual axes. A group of Zelkova trees was introduced to reflect local flavor. The existing pine grove was preserved as a symbolic 'park' for the Gumpo district. The outdoor amphitheatre within the grove was introduced by utilizing the existing topography, The flow of 'nature'on the deck area was designed to connect Mt. Gumkae with the 'city'. It is a comfortable resting place for its employees and visitors.

• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.157-159
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• 2003

Much of northern Asia is lacking in high-resolution palaeoclimatic data coverage. This vast region thus represents a sizeable gap in data sets used to reconstruct hemispheric-scale temperature trends for the past millennium. To improve coverage, we present a regional-scale composite of four tree-ring width records of Siberian pine and Siberian larch from temperature-sensitive alpine timber-line sites in Mongolia. The chronologies load closely in principal components analysis (PCA) with the first eigenvector accounting for over 53% of the variance from ad 1450 to 1998. The 20-year interval from 1974 to 1993 is the highest such growth period in this composite record, and 17 of the 20 highest growth years have occurred since 1946. Thus these trees, unlike those recently described at some northern sites, do not appear to have lost their temperature sensitivity, and suggest that recent decades have been some of the warmest in the past 500 years for this region. There are, however, comparable periods of inferred, local warmth for individual sites, e.g., in 1520-1580 and 1760-1790. The percent common variance between chronologies has increased through time and is highest (66.1%) in the present century. Although there are obvious differences among the individual chronologies, this result suggests a coherent signal which we consider to be related to temperature. The PCA scores show trends which strongly resemble those seen in recent temperature reconstructions for the Northern Hemisphere, very few of which included representation from Eurasia east of the Ural Mountains. The Mongolia series therefore provides independent corroboration for these reconstructions and their indications of unusual wanning during the twentieth century.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.32.2-32.2
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• 2013

We examine large-scale environmental effects on the formation and the mass growth of dark matter halos. To facilitate this, we constructed dark matter halo merger trees from a cosmological N-body simulation, which enabled us to trace the merger information and the assembly history of individual halos. In fact, since the massive halos are more likely to be distributed in denser regions than in less dense regions (Mo & White, 1996), the large-scale environment dependence of the properties of halos can be partly originated from the halo mass effect. In order to avoid such contamination, caused by the mass dependence of halo properties, we carefully measured the local overdensity as the indicator of large-scale environment, which was calculated to be as independent of halo mass as possible. Small halos (${\sim}10^{11-12}M_{\odot}$), which usually host isolated single galaxies, show a notable difference on the formation time of galaxies depending on their large-scale environments, which reconfirms halo assembly bias (Gao & White, 2007). Furthermore, we investigate how this environmental effect on small halos is correlated with the mass assembly history of galaxies by using our semi-analytic model. We found that assembly bias in small halos does not have significant effects on the formation time or on the star formation history of galaxies residing in those halos except for the individual stellar mass of galaxies at z = 0. On average, isolated galaxies in high-density regions tend to be slightly more massive than those in low-density regions. Although the observational data from the current galaxy surveys is not yet sufficient for testing this prediction, future galaxy surveys will be able to explore these small galaxies more thoroughly.

• Korean Journal of Remote Sensing
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• v.26 no.1
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• pp.9-20
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• 2010

The LIDAR data can be efficiently utilized for automatic reconstruction of 3D models of objects on the terrain and the terrain itself. In this paper, we attempted to generate simulated waveforms of FW (Full-Waveform) LIDAR (LIght Detection And Ranging). We performed the geometric modeling of the sensor and objects, and the radiometric modeling of the waveform intensity. First, we compute the origins and directions of the sub-beams by considering the divergence effects of a laser beam. We then searched for the locations at which the sub-beams intersected with the objects, such as ground, buildings and trees. Finally, we generate the individual waveforms of the reflected sub-beams and the waveform of the entire beam by summing the individual ones. With the experimental results, we confirmed the waveforms were reasonably generated, showing the characteristics of the surfaces the beam interacted with.

• Journal of Korean Society of Forest Science
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• v.32 no.1
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• pp.73-86
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• 1976

Two individuals ($sp_1$, $sp_2$) of purple and one individual ($sd_1$) of red hearted flower were selected from 18 years old Hibiscus syriacus trees obtained from the seeds treated with colchicine, and their morphological and physiological characteristics were investigated and following results were obtained. 1. The somatic chromosome number of the selected individuals, $sp_1$, $sp_2$, and $sd_1$ were 2n=160, while that of the check tree was 2n=80, indicating that the selected individuals, $sp_1$, $sp_2$ and $sd_1$ were tetraploid. 2. Peroxidase isoenzyme bands of high activity in selected individuals, $sp_1$, $sd_1$ and check tree were mostly in cathode, fixed band was f and v bands, and frequency of each band and their activity were not different between selected individuals, $sp_1$ and $sd_1$ and check tree. 3. The flowers of $sp_1$ individual were large in size and more dark purple than check tree's. The flowers of $sp_2$ individual were not increased in size, but they were dark purple and red heart at the base of the petal was expanded to 2/3 of the petal length. The flower of $sd_1$ individual was also large and some of the red lines from the petal base were extended to 2/3 of the petal length, which was much longer than those of the check tree. 4. Thickess of leaves, length of guard cells, diameter of pollens, wood fiber lengths and woody fiber widths were all increased in $sp_1$, $sp_2$ and $sd_1$ as compared to those of the check tree. 5. Survival percentage of cuttings was 80% with $sp_1$ and 36% with $sd_1$, and their growth performance were inferior to control in their second growing season.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.4
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• pp.327-339
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• 2020

Transpiration is the movement of water into the atmosphere through leaf stomata of plant, and it accounts for more than half of evapotranspiration from the land surface. The measurements of transpiration could be conducted in various ways including eddy covariance and water balance method etc. However, the transpiration measurements of individual trees are necessary to quantify and compare the water use of each species and individual component within stands. For the measurement of the transpiration by individual tree, the thermometric methods such as heat dissipation and heat pulse methods are widely used. However, it is difficult and labor consuming to maintain the transpiration measurements of individual trees in a wide range area and especially for long-term experiment. Therefore, the sharing of sapflow data through database should be useful to promote the studies on transpiration and water balance for large spatial scale. In this paper, we present sap flow database, which have Granier type sap flux data from 18 Korean pine (Pinus koraiensis) since 2011 and 16 (Quercus aliena) since 2013 in Mt.Taehwa Seoul National University forest and 18 needle fir (Abies holophylla), seven (Quercus serrata), three (Carpinus laxiflora and C. cordata each since 2013 in Gwangneung. In addition, the database includes the sapling transpiration of nine species (Prunus sargentii, Larix kaempferii, Quercus accutisima, Pinus densiflora, Fraxinus rhynchophylla, Chamecypans obtuse, P. koraiensis, Betulla platyphylla, A. holophylla, Pinus thunbergii), which were measured using heat pulse method since 2018. We believe this is the first database to share the sapflux data in Rep. of Korea, and we wish our database to be used by other researchers and contribute a variety of researches in this field.

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.422-430
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• 2014

This study was conducted to investigate growth changes of DBH, height, crown width, volume, stem biomass, and dead trees after thinning treatments with different thinning intensity for Korean white pine (Pinus koraiensis) plantation. First thinning was applied with 29~69% intensity based on number of trees in 19-yearold plantation, and trees were measured three times: right after thinning (19-year-old), 5 years later (24-yearold), 12 years later (29-year-old). In the case of DBH growth, average DBH growth of heavily thinned plots was 19.6~19.9% higher 5 years later, and 13.3~24.7% higher 12 years later, compared to that of unthinned plots. Initial diameter growth rate was higher than late growth rate. The proportion of large pole candidates ($DBH{\geq}25cm$) was 31% in heavily thinned plot while only 2% was shown in unthinned plot. No difference was shown in height growth depending on plots, and average crown width growth in heavily thinned plots was 30.6~33.3% higher, 5 years later, and 35.0~40.0% higher, 12 years later, compared to that of unthinned plots. Average volume growth of individual trees in heavily thinned plots was 39.8~46.8% higher, 5 years later, and 23.0~52.0% higher, 12 years later, compared to unthinned plots. The maximum volume and biomass per unit area were shown in unthinned plot; the volume and biomass 5 and 12 years later after thinning were $133m^3/ha$ (51 kg/ha) and $344m^3/ha$ (132 kg/ha), respectivily. The significant difference appeared in crown width, volume, and biomass depending on thinning intensity. No dead trees occurred in heavily thinned plots for 12 years after thinning, while mortality rate in unthinned plots was 27.9~37.8%. As a result of analyzing annual increment using cores to determine the timing of second thinning, it suggested that second thinning be suitable around 10 years after first thinning.