• Journal of Forest and Environmental Science
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• v.32 no.2
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• pp.189-195
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• 2016

Logging equipment and method have a major influence on harvesting productivity and cost. This study investigated the productivity and operational costs of tree-length cable yarding system using HAM300, a domestically developed tower yarder. We tested HAM300 for thinning operation in Pinus densiflora stands at Gangreung, Gangwon-do on April, 2014. To assess the productivity we conducted time study for each stage of the operation. When the average time/cycle was examined for each stage of the operation, the longest was for yarding (241 sec), followed by delimbing (237 sec), felling (153 sec), and processing (103 sec). Furthermore, productivity for felling was $8.6m^3/hr$, followed by delimbing ($5.1m^3/hr$), yarding ($3.5m^3/hr$), and processing ($8.1m^3/hr$). The total cost for the tree-length logging system was $58,446won/m^3$, of which the majority was incurred by the yarding cost at $46,217won/m^3$ (79.3%), whereas the lowest cost was for felling at $2,359won/m^3$ (4.1%). We suggest that it is necessary to foster specialized operators and provide training in operating the tower yarder thereby implementing efficient harvesting system resulting from low-cost yarding.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.317-323
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• 2012

Fragmented urban forests, as green islands within urban area, are the primary habitats for a vast number of different organisms inhabiting large cities. The areas of the urban forests are usually small, and hence, the proportion of the forest edge is relatively high. It is therefore expected that overall butterfly diversity may be lower than that of suburban or rural forests, and that those of grassland species, forest edge species, and generalist species with a wider niche breadth may be richer. Butterflies were surveyed weekly by the line transact method in order to characterize the butterfly community of the Hongneung Forest, a fragmented urban forest in Seoul. Butterfly richness of the study forest is much lower than those of main forests around or in Seoul. Grassland species, forest edge species, and generalist species were found to be richer, which was in agreement with the expected patterns of urban butterfly communities. Also, an endangered species, Spindasis takanonis, was observed in the Hongneung Forest, showing that urban forests play important roles for conservation of rare species.

• Journal of the Korea Society of Computer and Information
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• v.28 no.2
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• pp.99-110
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• 2023

In this paper, we propose a system termed ForestLi that can accurately estimate the diameter at breast height (DBH) and tree height using LiDAR point cloud data. The ForestLi system processes LiDAR point cloud data through the following steps: downsampling, outlier removal, ground segmentation, ground height normalization, stem extraction, individual tree segmentation, and DBH and tree height measurement. A commercial system, such as LiDAR360, for processing LiDAR point cloud data requires the user to directly correct errors in lower vegetation and individual tree segmentation. In contrast, the ForestLi system can automatically remove LiDAR point cloud data that correspond to lower vegetation in order to improve the accuracy of estimating DBH and tree height. This enables the ForestLi system to reduce the total processing time as well as enhance the accuracy of accuracy of measuring DBH and tree height compared to the LiDAR360 system. We performed an empirical study to confirm that the ForestLi system outperforms the LiDAR360 system in terms of the total processing time and accuracy of measuring DBH and tree height.

• Proceedings of the Plant Resources Society of Korea Conference
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• v.18 no.1
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• pp.94-95
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• 2005

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.04a
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• pp.173-173
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• 2005

• Proceedings of the Plant Resources Society of Korea Conference
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• 2009.10a
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• pp.46-46
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• 2009

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.1
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• pp.58-68
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• 2015

This study compares the wind stability of Larix kaempferi (Lamb.) Carr., Pinus koraiensis Sie. & Zucc. and Abies holophylla Maxim. to understand and inform wind risk management of these plantation trees at Daegwallyeong, Korea. Temporary square plots of $20m{\times}20m$ ($400m^2$) were laid out, and DBH (Diameter at Breast Height) and height for trees greater than 10 cm in DBH were measured by species. A total of 15 plots with 5 plots each in L. kaempferi, P. koraiensis and A. holophylla stands were sampled at random. Among the species, A. holophylla and P. koraiensis have comparatively lower h/d (Height/DBH) ratios than L. kaempferi. These results indicate that the former two species are more wind firm than the latter species. About 9% of the L. kaempferi trees have higher h/d ratios than the critical threshold limit 80. These trees are vulnerable to wind damage and should be removed in the next thinning regime. The analysis of variance detected a significant difference (p < 0.05) in the h/d ratios and Gini coefficient indicating species differences and DBH size variation, respectively. Gini coefficient was 16.4% in A. holophylla, 15.9% in P. koraiensis and 14% in L. kaempferi stands indicating limited DBH size variation. Lower h/d ratios are attributed to thinning in these stands and tree morphological differences. To increase wind firmness, low thinning should concentrate to remove trees with the h/d ratio above 80 coinciding at the time of stand distinction phase. Forest managers and practitioners should measure and maintain h/d ratios of trees below the critical threshold limit of 80 through stand density management. Variable density thinning approach should be tested to increase tree DBH sizes of the even-aged stands.

• Journal of Forest and Environmental Science
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• v.34 no.1
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• pp.53-56
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• 2018

Elemental carbon (EC) and organic carbon (OC) mass concentrations in PM2.5 were measured from March through October 2015 in Taehwa Research Forest (TRF). The concentration of carbon in the TRF was $3.4{\mu}g/m^3$ and the concentration of EC was $1.4{\mu}g/m^3$. Also the concentration of $OC_{sec}$ was the highest at $2.84{\mu}g/m^3$ in the summer and the lowest at 1.66 in the spring. The ratio of the secondary generation OC in the total OC was the highest at 62% in the summer. Monthly OC concentration was the lowest at $2.38{\mu}g/m^3$ in April and the highest at $6.60{\mu}g/m^3$ in July. In case of EC concentration was the lowest in April ($0.98{\mu}g/m^3$) and the highest in July ($3.41{\mu}g/m^3$). The OC/EC ratio showed the lowest ratio in March and the highest rate in September. It is suggested that the secondary generation reaction of OC component was active due to sufficient irradiation amount in summer.

• Journal of Korean Society of Forest Science
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• v.96 no.5
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• pp.539-542
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• 2007

This study was carried out to investigate the impacts of jasmonic acid (JA) on adventitious root culture of Eleutherococcus senticosus. Adventitious root of E. senticosus were treated with jasmonic acid (JA) and cultured for 30 days. JA inhibited the root growth but increased eleutherosides accumulation, total phenolic contents and antioxidant activity. Among various concentrations of JA, 1.0 mg/L JA increased the total phenolic contents in E. senticosus adventitious root to $39.81{\mu}g/g$, about 2.6 times higher than that of the control. Consequently, high accumulation of total phenolic contents led to increase the antioxidant activity to 82.41%. The antioxidant activity of control was 37.89% at $2500{\mu}g/mL$. A linear correlation ($R^2$ = 0.9937, 0.9648 and 0.9883) was also shown between antioxidant activity (at 1250, 1875, and $2500{\mu}g/mL$) and total phenolic contents of adventitious root of E. senticosus.

• Journal of Korean Society of Forest Science
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• v.96 no.5
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• pp.580-584
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• 2007

Actinidia arguta extracts obtained from three cultivars ('Sae-Han', 'Dae-Sung', and 'Chil-Bo') were assayed for their antioxidant properties and nutritional composition. Antioxidant activity of the extracts was evaluated using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. Total phenolic contents of the extracts were determined by the Folin-Ciocalteu method. Vitamin C (L-ascorbic acid) content measured by a colorimetric method and reducing sugar content estimated by dinitrosalicylic acid (DNSA) method. Crude extracts from A. arguta 'Sea-Han' showed the most potent radical-scavenging activity showing 86.55% at 10 mg/ml. The DPPH radical scavenging activity of extracts and solvent fractions from Sea-Han cultivar was in decreasing order of EtOAc fraction>BuOH fraction>$CH_2Cl_2$ fraction>hexane fraction, among which EtOAc fraction showed the highest antioxidant activity (87.51 % at 5 mg/ml). Total phenolic contents in A. arguta 'Sae-Han', 'Dae-Sung' and 'Chil-Bo', were 32.93, 28.23, and 25.60 mg/g, respectively. Vitamin C contents of them were 840.57, 578.81 and 730.10 ug/g, respectively.