• Journal of Korean Society of Forest Science
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• v.97 no.5
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• pp.485-491
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• 2008

This study was performed in 14 unthinned Mongolian pine (Pinus sylvestris L. var. mongolica Litvin) plantations in northeast China. Data were collected on 70 sample trees of different canopy position with diameter at breast height (DBH) ranging from 6.9 cm to 34.5 cm. Diameter and length of knots per whorl below the living crown were studied by different vertical levels divided by relative knot height (RHK) in this paper. Models taking DBH and height to the crown base (HCB) as independent variables were developed to predict knot diameter (KD) in a sample whorl. According to the vertical distribution tendency and range of sound knot length (KLsound), KLsound was modeled as multiple linear function of DBH, KD and relative knot height (RHK). The loose knot length (KLloose) was described as a function of DBH, KD and height above the ground for knots (HK) in a mixed log-linear model. Results from this study can provide abundant knot information so as to describe the knot size and vertical distribution tendency of Mongolian pine plantation.

• Journal of Forest and Environmental Science
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• v.31 no.2
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• pp.73-77
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• 2015

Acquiring accurate quantitative and qualitative information is necessary for the technical and scientific management of forest stands. In this study, stratification and systematic random sampling methods were used to estimation of quantitative characteristics in study area. The estimator ($((E%)^2xT)$) was used to compare the systematic random and stratified sampling methods. 100 percent inventory was carried out in an area of 400 hectares; characteristics as: tree density, crown cover (canopy), and basal area were measured. Tree density of stands was compared through systemic random and stratified sampling methods. Findings of the study reveal that stratified sampling method gives a better representation of estimates than systematic random sampling.

• Journal of Forest and Environmental Science
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• v.15 no.1
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• pp.1-9
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• 1999

Noticing the intrinsic growing habit variations of hardwood species which is indigenous to the natural deciduous forest, eighteen tree species in overstory were selected for comparative evaluating tree form so as to develop the tree form index (TFI). Selected six tree form attributes were arbitrarily divided four assessment criteria and given appropriate scores. Eighteen tree species were undergone corresponding scores, converted to percentage base, and estimated TFI by the summation of the six scoring values. Cluster analysis was carried out to review which attribute would have been shared among species based on dissimilarity of scores for each pair of species in $18{\times}6$ data matrix. The result showed that Populus davidiana had the highest TFI value of 80.8 and Carpinus cordata had the lowest TFI va1ue of 46.3. The species which received more than 70 of TFI are Populus davidiana, Betula costata, Fraxinus mandshurica, and Ulmus davidiana var. japonica, characterized by the advantage of straight and longer bole, the narrower crown, and the thinner branch. On the contrary, such species as Sorbus alnifolia. Prunus sargentii, Acer mandshuricum, Juglans mandshurica, and Carpinus cordata received less than 60 of TFI, characterized by the disadvantage of the crooked or forked stem. the wider or deeper crown. and the thicker branch. In the dendrogram produced by cluster analysis, arbitrary value of Euclidean distance 10 divided eighteen species into four distinctive groups. and the typical characteristics of each group were discussed.

• Journal of Ecology and Environment
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• v.34 no.2
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• pp.157-165
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• 2011

This study was conducted to determine the characteristics of gaps and natural regeneration of trees on Mt. Makiling, the Philippines. Canopy gaps in or around two 1-ha permanent plots and on 3-km line transects were investigated. Most of the gaps studied were formed or affected by Typhoon Milenyo, which hit the study site in September 2006. The most frequent mode of gap maker death was snap-off, whereas uprooting was relatively less important. The most frequent gap maker was balobo (Diplodiscus paniculatus) followed by magabuyo (Celtis luzonica) and katmon (Dillenia philippinensis). In contrast, the most frequent gap filler was magabuyo (C. luzonica). At the sapling layer, the most important species was magabuyo (C. luzonica), but there was a high proportion of lianas and palms. Most of the gaps had leaf area index (LAI) values between 3 and 5. A clear trend of a decrease in gap size and an increase in LAI was observed for 2 years from 2007 to 2009. New seedlings emerged very abundantly during the same time period. The rapid changes in the gaps were partially due to the excellent capability of tropical trees to resprout after the crown or stem was damaged by the typhoon. This study on gap dynamics may contribute to a better understanding of the natural regeneration process of trees in tropical rainforests.

• Korean Journal of Environment and Ecology
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• v.21 no.1
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• pp.47-54
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• 2007

This study was conducted to clarify the characteristics of habitat structure and bird communities between natural deciduous forest and around the road from October 2005 to August 2006 in the National Arboretum, Gwangneung, Korea. There were more larger trees and higher coverage of crown canopy in the natural deciduous forest than around the road. A total thirty seven species of birds were observed in the natural deciduous forest and twenty species were around road. The observed number of bird species and individuals, and bird species diversity index (H') were higher in the natural deciduous forest in each season. Foraging and nesting guild structures were also different. The differences of characteristics of bird communities would be related with habitat structure between both study areas.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.4
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• pp.67-74
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• 2016

Drone images with high spatial resolution are emerging as an alternative to previous studies with extraction limits in high density forests. Individual tree in the dense forests were extracted from drone images. To detect the individual tree extracted through the image segmentation process, the image segmentation results were compared between the combination of DSM and all R,G,B band and the combination of DSM and R,G,B band separately. The changes in the tree density of a deciduous forest was experimented by time and image. Especially the image of May when the forests are dense, among the images of March, April, May, the individual tree extraction rate based on the trees surveyed on the site was 50%. The analysis results of the width of crown showed that the RMSE was less than 1.5m, which was the best result. For extraction of the experimental area, the two sizes of medium and small trees were extracted, and the extraction accuracy of the small trees was higher. The forest tree volume and forest biomass could be estimated if the tree height is extracted based on the above data and the DBH(diameter at breast height) is estimated using the relational expression between crown width and DBH.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.1
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• pp.46-54
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• 2021

This study compared and analyzed the effects of forest tending works on the vertical distribution of wildfire fuel loads on Pinus densiflora stands in Gyeongbuk province. The study sites were located in Youngju and Bonghwa in Pinus densiflora stands. A total of 10 sample trees were collected for the development of the crown fuel vertical distribution model. The 6th NFI (National Forest Inventory) selected a sample point that only extracted from managed and unmanaged stands of Pinus densiflora in the Gyeongbuk province. The fitness index (F.I.) of the two models developed was 0.984 to 0.989, with the estimated parameter showing statistical significance (P<0.05). A s a results, the vertical distribution of wildfire fuel loads range of unmanaged stands was from 1m to 11m with the largest distribution at point 5m at the tree height. On the other hand, the vertical distribution of wildfire fuel loads range of the managed stands was from 1m to 15m with the largest distribution at the point of 8m at the tree height. The canopy bulk density was 0.16kg/㎥ for the managed stands and 0.25kg/㎥ for the unmanaged stands, unmanaged stands were about 1.6 times more than managed stands. This result is expected to be available for simulation through the implementation of the 3D model as crown fuel was analyzed in three dimensions.

• Korean Journal of Environment and Ecology
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• v.28 no.3
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• pp.342-356
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• 2014

This study aims to provide the fundamental data for restoration through the analysis of vegetation structure characteristic for managed area with deforest and fumigation among the places damaged by oak wilt disease in Bukhansan National Park. Study areas were selected in six damaged areas with 18 plots ($20m{\times}20m$) including comparing plots between year 2006 and year 2011 after preliminary study finding the exact location with easy access. Analysis items are density and coverage of under story layer, Importance Percentage of under story layer and Importance Percentage of urban adapted species and alien species. As a result, density and coverage under the canopy layer's vegetation was higher than comparing plot in Musugol valley and Soquicheon valley which 4 years and more passed. And Wondobong, Darakwon, Doseonsa and Dobong valley which had not been passed 3 years after deforestation and fumigation decreased in those of vegetation. However, the plots in Wondobong and Doseonsa was analyzed to be higher in density of shrubs than comparing plot. In terms of distirbution of species in under canopy layer which is grown as a upper vegetation, Quercus serrata and Sorbus alnifolia dominated each other in under canopy layer except for Wondobong and Darakwon. Wondobong continuously maintained Quercus mongolica and Q. mongolica and Pinus densiflora dominated in under canopy layer of Darakwon. S. alnifolia which is Urban adapted species were distributed in most study areas. In terms of alien species, Magnolia obovata and Robinia pseudoacacia were newly intruded in the opened crown, and Pueraria thunbergiana was distributed in Soquicheon valley. As the result of soil analysis, acidification(pH 4.49) and low level of organic matter(3.23%), available phosphate(1.40mg/kg) and exchangeable cation were analyzed and it was considered that those environment poorly support the vegetation growth.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.590-598
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• 2015

Despite various control methods for pine wilt disease, the disease has been increasing at an alarming rate every year in Korea. Still there is a lack of research on the problems of the current methods used to curb the disease. One main method to control pine wilt disease is fumigation for eliminating the larva of the pine sawyer beetle (Monochamus alternatus) which is known as the vector insect for pine wilt disease. We surveyed and analyzed the amount of destroyed uninfected trees in the fumigated area by studying 32 survey plots ($100m^2$) in Miryang city. The destroyed trees' crown area was estimated by induced regression between root collar area and crown area of the remaining trees (coniferous tree: $R^2=57.4$, deciduous broad-leaved tree: $R^2=63.8$). According to the analysis results, the infected trees (cut trees) were 18.7% and cut trees which were not infected were 35.5% of the total tree population of the study area on the basis of total crown area. In case of pine trees, 8.4% of uninfected trees were cut off but 62% of uninfected deciduous broad-leaved trees including Quercus spp. were affected and damaged during the fumigation process. Since these broad-leaved trees dominate the sub-canopy layer of the forest, this indiscriminate interruption of broad-leaved trees has the adverse effect of depriving the public benefits such as shadow, a cooler weather, controlling humidity, etc.

• Korean Journal of Environment and Ecology
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• v.24 no.2
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• pp.157-165
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• 2010

This study was carried out to suggest the basic data of planting method for construction of buffer green space based on the land use in case of reclaimed land by analyzing land structure, planting concept, and planting structure in buffer green space, Rokko Island, Kobe, Japan. Rokko Island(total area: 580ha) is divided into port and logistics industry area and urban area by constructing the box type large-scale buffer green space. The land structure of buffer green space were biased mounding type, parallel mounding type, and complex mounding type. The width of buffer green space was 50meters in case of northern area, from 28 to 32meters in case of eastern area, and 37.5meters in case of western area, and the slope of that was from 18 to 25 degrees and the height of that was from 2 to 15meters. There were applied landscape and buffer planting concept on the sea side area of northern buffer green space, on the other hand landscape and shade planting concept on the Inner city side area of that. According to the result of planting structure analysis of northern buffer green space, the main woody species were those of deciduous-evergreen species grow in warm-temperate forest zone such as Quercus glauca, Cinnamomum camphora, Machilus thunbergii, Elaeagnus maritima. The results of maximum number of species and planting density by $100mm^2$ was that 9 species 22 individuals in canopy layer, 9 species 15 individuals in understory layer, 3 species 67 individuals in shrub layer, and 14 species 104 individuals in total. The plant coverage of northern buffer green space based on the ecological planting method was from 69 to 139% in case of canopy layer, from 26 to 38% in case of understory layer, from 6 to 7% in case of shrub layer, and from 101 to 184% in total. Index of plant crown volume of northern buffer green space based on the ecological planting method was from 1.40 to $3.12m^3/m^2$ in case of canopy layer, from 0.43 to $0.55m^3/m^2$ in case of understory layer, $0.06m^3/m^2$ in case of shrub layer, and from 1.89 to $3.73m^3/m^2$ in total.