• Korean journal of applied entomology
• /
• v.34 no.3
• /
• pp.174-180
• /
• 1995

The damage rate according to the age of black pine trees in the Black pine bast scale, Matsucoccus thunbergianae was high from 7 to 22 year old trees. According to damaged degree of damaged trees, it showed great difference in infection rate of saprophitic fungi. The period until the developmental degree of saprophitic fungi became maximized degree of 7 was required about 48 days in dead tree of 100 percent, about 54 days in one of above than 80 percent, about 75 days in one of 40~50 percent, but the dead tree less than 10 percent and health tree was retained the 3~4 developmental degree of saprophitic fungi, after 80 days. The ring width of damaged trees showed as follows. The non damaged trees was 3.52 cm, 0.77 cm in the damaged trees of 100 percent, 0.88 cm in the ones of 80 percent, 1.22 cm in the ones of 40~50 percent and 1.37 cm in the ones of les than 10 percent, respectively. Number of cells per unit area was smaller in the case of greater damaged trees, gradually. Also moisture content was very high in greater damaged trees, and bending strength was lower. Extracts by the one percent NaOH showed a small amount.

• Journal of the Korean Wood Science and Technology
• /
• v.33 no.6 s.134
• /
• pp.8-16
• /
• 2005

Fire-killed trees of Korean red pine are valuable resources for industrial uses. It is common only believed that fire-killed trees are too weak and brittle to use in construction purposes. The misunderstandings of fire-killed trees lead these valuable resources abandonment. The purposes of this research are focused on scrutinization of material properties of fire-killed trees to facilitate industrial uses of these resources. The sample logs were collected from the forest fire site of the eastern coast area in which the most catastrophic wild fire had taken place in 2000. Fire-killed Korean red pines were classified into 3 levels by the degree of fire damage so called light, medium and heavy, then their physical, mechanical and chemical properties were compared with sound trees. No significant difference in physical appearances were found in the cross sections by degree of damage compared to sound tree but bark char. Investigation on mechanical and chemical properties indicates that forest fire did not impact significantly in lowering the strength of damaged trees. It was concluded that there was any limitation of forest fire-killed trees of Korean red pine in industrial utilization.

• Journal of Ecology and Environment
• /
• v.38 no.2
• /
• pp.175-183
• /
• 2015

Extremely strong winds and heavy rainfall caused canopy gaps in a mixed Abies holophylla broadleaf forest and a Quercus mongolica-dominated forest in Odaesan National Park, Korea in October 2006. The impact of the combination of strong winds and torrential rain on the development of forest gaps and canopy structures were investigated. The mean size of newly created gaps were $205m^2$ in the mixed forest and $86m^2$ in the Quercus forest, and were created by 2.8 and 1.4 gapmaker trees, respectively. Among the 73 trees lost in the mixed forest, 59% succumbed because of direct wind damage while 41% were struck by neighboring trees that fell into them. Most of these trees downed by wind were uprooted (74%), while the trees downed by neighboring tree falls snapped (78%). 21 trees in the Quercus forest died from direct wind damage, and 57% of them were uprooted. Although the relative density of Abies nephrolepis and A. holophylla represented only 0.2% and 6.4%, respectively, of all species in the intact mixed forest, they accounted for 27% and 15%, respectively, of all trees affected by wind on that site. In fact, 85% of the total A. nephrolepis and 91% of the total A. holophylla in the mixed forest fell directly due to strong wind. By contrast, only one Abies species, A. nephrolepis, was found in the Quercusdominated forest, and it accounted for 7.3% of the species composition. These findings suggest that A. nephrolepis and A. holophylla are particularly susceptible to high winds because of their great heights and shallow root systems.

• Journal of Environmental Science International
• /
• v.25 no.1
• /
• pp.127-134
• /
• 2016

This study is conducted to get current state of data collection and utilization of the trees damaged by pine wilt disease, and to efficiently collect and utilize of the trees damaged by the pine wilt disease and abandoned fumigation-treated trees at forecasts. The method to control pine wilt disease damaged area is mostly fumigation treatment system, and there is no collection and utilization of damaged trees because of absence of efficient collection system, lack of collection cost, and absence of policy, etc. A survey is conducted that asked about the satisfaction degree for the trees damaged by pine wilt disease collection and use divided into 6 topics. It was positively recognized that the need and problem of the trees damaged by pine wilt disease, and results and satisfaction of forestry mechanization while it was mostly negatively recognized that the policy satisfaction for prevention and collection, satisfaction of collection and use, collection and forestry mechanization, and satisfaction of foundation equipment for forestry mechanization, etc. As a result of path analysis, it is necessary to promote a high-tech forestry mechanization to improve satisfaction level of results and satisfaction of forestry mechanization for the trees damaged by pine wilt disease collection and utilization, it is also need to make an effort in various ways for improve satisfaction level of satisfaction of collection and utilization.

• Journal of Korean Society of Forest Science
• /
• v.95 no.1
• /
• pp.1-4
• /
• 2006

Closing processes of taping holes and diameter growth of taped trees of Acer mono were investigated to understand the effects of sap taping and number of tapping holes on tree growth and closing speed of holes. Closing processes of tapping holes were faster at trees taped of ten holes than trees tapped of one, three, five holes during the study period, and tapped holes were completely filed up within 15 months. Diameter growth by number of tapped hole were 0.54 mm for control trees, 0.60 mm for trees taped of one hole, 0.64 mm for trees taped of three holes, 0.33 mm for tapped of five holes and 0.31 mm for trees taped of ten holes, respectively. Closing processes of tapping holes by fusion materials was fast in the order of DB ointment, stirofoam, control and bamboo vinegar. Especially, tapped holes in the case of DB ointment was completely healed within 4 months. Therefore, DB ointment should be used to minimize damage on tree growth and secure resources for sap collection of A. mono.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.3 no.1
• /
• pp.57-68
• /
• 2000

The purpose of this study is to find the most effective method of the coding methods by linking the attribute information with the digital map in Taegu metropolitan city. This study was also a precedent plan for street trees management information system and the coding schemes for street trees management information system could be summarized as follows; First, this study extracted 11 coding factors for expressing the position of street trees. Second, 11 coding schemes were made out of these coding factors and applied to the digital map(1:500). Third, two methods of 11 coding schemes were selected for street trees management information system of Taegu metropolitan city. The one was the method which applied serial numbers according to the block name. The other was the method utilizing the concept of 'dynamic segment'. Finally, this study will be the first step for the computerization and management of the street trees information and this computerized data will do for the management efficiency of the street trees on internet.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.6 no.2
• /
• pp.27-38
• /
• 2003

This study aimed to provide basic data for future management of roadside trees by analyzing problems associated with plantation and management of roadside trees through categorization of functions and organizational structure, plantation and management, and management regulations and generating improvement opportunities based on the result of a survey on the awareness of government officials who are directly in charge of managing roadside trees in 31 cities & counties within Kyonggi province. The summary of key results of this study is as follows. First, "roadside tree-related function" is still not considered to be independent. About a half of government officials in charge did not majored in this field and they spent only about "2.09hours", in average, in the roadside tree-related function out of 8 working hours per day. Second, regarding problems and improvement opportunities in roadside tree-related function, lack of time was considered to be the biggest problem in overall management of roadside trees. As for improvement opportunities, "increase of dedicated manpower" and "system development" to facilitate efficient processing were suggested. Third, an annual budget for roadside tree-related affairs was merely 92 million won per city/county. A registry for management of roadside trees was kept manually. As for the roles of roadside trees, improvement of landscape and securing of green area itself were valued highly. Fourth, Ginkgo biloba, Zelkova serrata, and Prunus yedoensis were suggested to be the most appropriate species for roadside tree and Platanus occidentalis, Populus albaglandulosa, Populus euramericana, and Robinia pseudo-acacia were mentioned to be the least appropriate species.

• Journal of People, Plants, and Environment
• /
• v.23 no.1
• /
• pp.115-123
• /
• 2020

With the aim of accumulating data that can be used to infer the basis for the acculturation of trees called 'Goe,' this study aims to identify the survival status of the pagoda and zelkova trees known as 'Goe' trees by comparing and analyzing the status of pagoda trees (Sophora japonica) and zelkova tree (Zelkova serrata) designated as a protected tree in Korea. The results of this study are as follows; Zelkova serrata designated as a protected tree grows the most, with 2,147 trees (29.4%) in Cheonnam, followed by Chungnam (16.5%) and Gyeongbuk (14.4%). However, Sophora japonica showed a different result from zelkova Serrata as the total number of 210 Sophora japonica (55.7%) in Gyeongbuk and Daegu is much larger than that of zelkova Serrata. As a result, in the Yeongnam region, where the Confucianism of Yeongnam was actively practiced, the existence of Sophora japonica is much larger than that of the Zelkova Serrata, which is not a coincidence, and it is difficult to determine it only based on their flora and planting distribution. Results of comparing protected trees of Sophora japonica and Zelkova Serrata showed that the average age of Zelkova Serrata wass 289 years, while that of Sophora japonica was 302 years, and that the average height of Zelkova Serrata wass 18 m, which is higher than the height of 16 m of Sophora japonica. The average diameter at breast height of Zelkova Serrata was 398 cm and that of Sophora japonica was 314 cm, which indicates that Zelkova Serrata is relatively big. Therefore, it can be assumed that Zelkova Serrata has a larger growth potential than Sophora japonica, and the possibility of growth as a big tree is also high, but it seems that the explanation that "they are relatively long-lived" is not clearly determined.

• Korean Journal of Environmental Agriculture
• /
• v.42 no.2
• /
• pp.104-111
• /
• 2023

As apple trees mature, it is important to maintain good light distribution within the canopy to produce marketable fruits. Tree thinning is the selective removal of a proportion of trees growing in the orchard to provide more growing space and a good light environment for the remaining trees. This study was conducted over 3 years (14-16 years after planting) to investigate the influence of tree thinning on vegetative growth, yield, fruit quality, and blooming in the 14 years old slender spindle 'Fuji'/M.9 apple trees planted with the tree space of 3.2×1.2 m. The trees were placed in a control group (no thinning; 260 trees per 10 a) or a tree thinning group (thinned 50% of the control; 130 trees per 10 a). The tree thinning successfully improved light penetration, yield per tree, fruit red color, and yield efficiency for 3 years, and the tree thinning controlled the occurrence of biennial bearing. However, tree thinning significantly decreased accumulated yield per 10 a compared with the control. The vegetative growth, yield per tree, soluble solid contents, and blooming were not clear by the occurrence of biennial bearing in the control. These results indicated that tree thinning was a good method for improving light penetration and preventing biennial bearing in the old 'Fuji'/M.9 high-density apple orchards.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.35 no.12
• /
• pp.555-559
• /
• 1986

It is shown that water tree grown using the water needle method in polyethylen do not behave as conductor but as dielectrics. It is decuded that water trees are not non-interconnected cavities. This result is confirmed by gas flow measurements through freeze-fractured water trees.