• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.6
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• pp.140-147
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• 2012

This study was conducted to investigate optimum planting density for apartment complex. The validity of Landscape Architecture Criteria of Korea was checked for it. We compared our field data with Landscape Architecture Criteria. In this step, the tree density of urban forest was regarded as standard. Field study was examined in 3 apartment complexes located in capital area, especially completed during these 10 years. 10 sites in each complex were selected and tree density per unit area were calculated. This field study data was divided standard size and large size which received weight. And, it was compared and analyzed. And crown projected area(CPA) was calculated considering proper growth of low vegetation and sufficient shade. The outcome shows that minimum size of Landscape Architecture Criteria is rational. But, in the case of planting large size tree received weight, tree density was short comparing with the tree density of urban forest and CPA was less than 50%. By the result of field study in 3 apartment complex, the tree density of apartment complex satisfied or exceeded Landscape Architecture Criteria. But, in the case of planting large size tree, tree density and CPA show high density due to addition planting for deficient landscape. Therefore, the revision of the Landscape Architecture Criteria was required such as deletion or minimization of the weighted clause about the large size tree and regulate the limit CPA not less than 50% and not more than 100%.

• Journal of Korean Society of Forest Science
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• v.95 no.4
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• pp.501-506
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• 2006

To study the regeneration process of tree species after clear cutting, we investigated the density of seedling occurred after 1 year in the coniferous forest of Sikotuko Hokkaido, northern Japan that was clearcut after windthrow damage due to typhoon. As the results, 25 species of tree seedlings were growing and the density of seedlings and sprouts was $9.8trees/m^2$ ($1.25tres/m^2{\sim}54.44trees/m^2$) in the area of clear cutting. The 87% ($8.6/m^2$) of all seedlings was current seedlings and non-animal dispersal seedlings (average density $7.2tree/m^2$) were about 5 times more than animal-dispersal seedlings ($1.4tree/m^2$). The seedling density was beyond $6tree/m^2$ within 10m and $2{\sim}9tree/m^2$ in 150~250m from a natural forest. Number of non-animal dispersal seedlings were decreased along the distance from a natural forest but there was not such a tendency in animal dispersal seedlings. The variation in seedling density was higher in non-animal dispersal seedling than in animal dispersal seedling. In natural regeneration of tree species after clear-cutting, the possibility that pioneer species like Betula spp. etc. will be composed of the major species is high. Therefore, in order to maintain the species diversity, the nurture work for reducing competition among the individuals is necessary.

• Journal of Korean Society of Forest Science
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• v.95 no.5
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• pp.595-600
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• 2006

The plot design influences the budgets and the precision of forest inventory results. The objective of this study is to determine the efficiency of estimating forest variables such as tree density, basal area, volume, and species richness based on various plot sizes using fixed-area plot sampling in the natural deciduous forest of Pyeong-Chang County, Gang-won Province, Korea. In this study, 108 reference plots were established with a fixed plot size and shape of 0.09 ha ($30m{\times}30m$). In order to determine the optimal plot size for the interest of variables, each sample plot was established using different shapes (square, circle, and rectangle) and was divided into different plot sizes from 100 to $900m^2$. The mean relative difference (MRD) for the sum of the basal area and volume, and tree density per hectare decreased as plot size increased. But the MRD for three variables were only below 13% at the plot size of $500m^2$. Species richness for each reference stand observed ranging from 2 to 15 species, demonstrated highly positive significant relationships with plot size. The minimum plot size for the estimation of tree density, the sum of the BA and volume was determined to be about $400m^2$, whereas the estimation of species richness required a minimum plot size of $500m^2$.

• Journal of Korea Foresty Energy
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• v.20 no.2
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• pp.46-57
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• 2001

This study was conducted to provide tending operation information for the effective management in unmanaged artificial forests of Pinus densiflora for. erecta, Pinus rigida, and larix leptolepis, based on the study of the comparison of tree growth pattern by residual stand density after thinning practices. Followings are summarized results of this study. 1. The diameter growth of residual trees was increased as residual stand density decreased by thinning practices in the stands of Pinus densiflora for. erecta, and Pinus rigida, and subcompartment (Ga) and (Na) of Larix leptolepis. The statistical analysis noted that the tree growth was significantly different by the residual stand density. 2. The height growth did not show corresponding results by stand density treatment pattern, which indicated that the height growth was not directly influenced by residual stand density, but by site quality of the stand. 3. The diameter increment for the last six years was proportionately increased in larger diameter classes and less dense stands.

• Journal of Korea Foresty Energy
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• v.18 no.2
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• pp.92-99
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• 1999

This study was carried out to understand the primary production of biomass, vertical biomass distribution in the stand and the difference of biomass production for part of the trees by stand density for natural Pinus densiflora forest at Mt. Baekdoo located in northeastern China. The primary production of biomass was estimated by the layers of trees, shrubs, herbs for five density classes. For the biomass estimation of the Pinus densiflora trees in stern, stembark and the above-ground tree, the regression model of logW = a + blog(D$^2$H) + c(D$^2$H) was adapted for all of the density classes where W is dry weight, D$_1$ diameter at breast height, and H, tree height. For the biomass estimation in branch and needle, and the needle area, the regression model of logW=a+blogD+cD was adapted for all of the density classes. With increasing stand density the biomass of trees increased but that of shrubs and herbs decreased. Net primary production of biomass in parts of the tree also increased with increasing stand density. However the percentage of the needle biomass among the total biomass in the above-ground tree decreased with increasing stand density. Consequently, primary production rate of biomass in the above-ground tree increased. The primary production of biomass for each part of the trees in natural Pinus densiflora natural forests showed in descending order : stern, needle, branch, and stembark regardless of stand density.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.774-780
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• 2001

Aboveground carbon storage and increment of a 31-year-old pitch pine (Pinus rigida) stand were measured for five years (1997~2001) in the Jungbu Forest Experiment Station, Gyeonggi-do, Korea. The carbon concentration in each component of aboveground and soil depth decreased in the order of needle>branch>stembark>stemwood>forest floor>0-15cm soil depth>15-30cm soil depth. The carbon storage except for root carbon was 140,600kgC/ha and the tree accounted for 61%, soil 31% and forest floor 8% of the stand carbon storage. Due to high tree mortality by Fusarium subglutinans infection and spring drought in 2001, carbon increment except for 2001 data was 3,233kgC/ha/yr and was in the order of stemwood>branch>stembark>needle. Carbon storage and increment were attributed to stand density and site quality. Carbon storage and increment were higher in the high site quality than in the lower site quality plot on similar tree density. Also, the high tree density site on similar site quality showed more carbon storage and increment compared with the lower tree density. The results suggest that site quality and tree density are a key factor determining carbon storage and increment in this pitch pine stand.

• Journal of the Korean Operations Research and Management Science Society
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• v.35 no.2
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• pp.71-88
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• 2010

A density-based outlier detection such as an LOF (Local Outlier Factor) tries to find an outlying observation by using density of its surrounding space. In spite of several advantages of a density-based outlier detection method, the computational complexity of outlier detection has been one of major barriers in its application. In this paper, we present an LOF algorithm that can reduce computation time of a density based outlier detection algorithm. A kd-tree indexing and approximated k-nearest neighbor search algorithm (ANN) are adopted in the proposed method. A set of experiments was conducted to examine performance of the proposed algorithm. The results show that the proposed method can effectively detect local outliers in reduced computation time.

• Korean Journal of Environment and Ecology
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• v.23 no.4
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• pp.365-375
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• 2009

The growth characteristics of Pinus thunbergii windbreak forest around Goosipo Beach, Sangha-Myon, Gochang-Gun, Jeollabuk-Do have been investigated, and the results are summarized as follows. The soil in the site was light acid sand with pH 5.7, and the mean sodium concentration of soils was 1.42dS/m. The tree diameter, height, crown width, and shape ratio(Height/DBH) were better with tree density was coming lower. Especially, the rate of shape ratio under 60 was more in sites with low tree density. This demonstrated that the trees have grown more soundly when the tree density was lower. The direction of main winds and distribution ratio of tree inclination had a correlation. The inclined trees are seemed to be influenced by main winds when they were younger and by Typhoon partly. Eighty one vascular plant species were found in the sites, and more number of herbaceous plants (57 taxa) lived there than woody plants (24 taxa). And more plant species of dune were found at the site where dune have developed well. Some thinning works need at high tree density areas in order to ensure effects of coastal windbreak.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.409-414
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• 1995

This study was carried out for the analysis and comparison about the noise diminution effects by the height, width and density of Euonymus japonica wall, the distance of sound source, the distance of sound receiver, the height of sound source, and the height of sound receiver. The results obtained were summarized as follows; 1. After the establishment of tree wall, the volume of noise diminution measured 6.8dB and the effects of noise diminution measured heigher than before by 10.6% and t-value was significant at the 1% level 2. In simple correlation between the effects of noise diminution and variables, the density of tree wall was found as the most significant factor, and the last were found in the order of the distance of sound receiver, the width of tree wall, and the distance of sound source. 3. In partial correlation coefficients the effects of noise diminution and variables, the density of tree wall (r=-0.959) was found as the most significant factor, and the last were found in order of the distance of sound receiver (r=-0.906) and the width of tree wall (r=-0.753). 4. The estimated equation to measure the effects of noise diminution according to variables (the height of tree wall, the width of tree wall, the density of tree wall, the distance of sound source, the distance of sound receiver, the height of sound source, and the height of sound receiver) was $Y=69.520-1.672X_1-1.656X_2-0.066X_3-0.248X_4-3.134X_5-0.222X_6-0.343X_7$, and the coefficient of determination of this estimated equation was highly found as 0.950. 5. In semi-partial correlation coefficient the effects of noise diminution were found in the order of the density of tree wall, the distance of sound receiver, the width of tree wall, and the height of tree wall from the highest to the lowest. Therefore, it was considered that the density of tree wall, the distance of sound receiver, the width of tree wall and the distance of sound source should be controlled effectively to increase the effects of noise diminution by Euonymus japonica wall.

• Journal of Forest and Environmental Science
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• v.34 no.2
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• pp.162-164
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• 2018

This study quantified the carbon storage and uptake by street trees in Seoul and explored suitable planting and management strategies. A systematic sampling model was used to select 50 plots to survey the structures of street trees. The average density and cover of street trees were approximately 5.8 trees/$100m^2$ and 12.1%, respectively. Trees with a dbh of less than 30 cm accounted for about 66.3% of the total number of trees surveyed. The total carbon storage and uptake by the street trees were approximately 103,641 t and 10,992 t/yr, respectively. The total carbon uptake equaled the amount of annual carbon emissions from driving of about 11,000 cars. Street tree planting and management strategies were proposed to enhance carbon uptake. They included multi-layered and multi-aged planting, securing ground and space for plant growth, and avoiding excessive tree pruning.