• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.4
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• pp.57-67
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• 2014

The vigor condition of trees is an important indicator for the management of urban forested area. But difficulties in how to assess the tree vigor condition still remain. Previous efforts were limited in the 1) measurement of single indicator rather than using multiple indices, 2) purpose-oriented measurement such as for air-pollution effect or specific pathological symptom, and 3) ordinal-scale evaluations by field crews 4) despite human errors based on his/her experiences or prior knowledge. Therefore, this study attempted to develop a quantitative and objective methodology for assessing tree vigor condition, by measuring multiple modules and building the profile inventory. Furthermore, the possibility and limitations were discussed in terms of schematic frames describing tree vigor condition. The vigor condition of 56 flowering cherry plants in urban park were assessed by in-situ measurements of following eight items; growth of crown(Gc), growth of shoots, individual tree volume(Vol), plant area index, woody area index, leaf area index, leaf chlorophyll content(Lc) and leaf water content(Lw). For validation, these measurements were compared with the ranks of holistic tree vigor condition, which were visually assessed using a 4-point grading scale based on the expert's knowledge. As a result, the measures of each evaluation item successfully highlighted a variety of aspects in tree vigor condition, including the states of both photosynthetic and non-photosynthetic parts. The variation in the results depending on evaluated parts was shown within an individual tree, even though the broad agreement among the results was found. The result of correlation analysis between the tested measurements and 4-point visual assessment, demonstrated that the state of water-stressed foliage of the season (Lw) or the development of plant materials since sapling phase (Vol) could be better viewed from the outer appearance of trees than other symptoms. But only based on the visual assessment, it may be difficult to detect the quality of photosynthesis (Lc) or the recent trend in growth of trees (Gc). To make this methodology simplified for the broad-scale application, the tested eight measurements could be integrated into two components by principal component analysis, which was labelled with 'the amount of plant materials' and 'vigor trend', respectively. In addition, the use of these quantitative and multi-scale indicators underlies the importance of assessing various aspects of tree vigor condition, taking into account the response(s) on different time and spatial scale of pressure(s) shown in each evaluated module. Future study should be advanced for various species at diverse developing stages and environment, and the application to wide areas at a periodic manner.

• Korean Journal of Environment and Ecology
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• v.35 no.4
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• pp.398-407
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• 2021

This study intended to identify causes of poor tree vigor in the Hanbando coastal forest by investigating its geographical environment, climate condition, soil physicochemical characteristics, and growth condition of Pinus thunbergii. It divided the forest into an area with poor tree vigor or dead standing trees and a control area with good tree vigor and examined them separately. The survey showed that stand density was significantly higher in the area with poor tree vigor. In contrast, the crown width in the area with good tree vigor was wider. The number of dead standing trees and the stand density showed a negative correlation. The stand density and diameter at breast height (DBH), tree height, crown height, and crown width also showed a negative correlation. The result indicated that, as the tree's stand density increases, the crowns of individual trees overlapped and the lower branches died. Then crown height and crown width decreased, and the number of leaves and photosynthesis was reduced, leading to lower tree height and weaker growth of breast diameter. As a result, tree vigor weakened, and combined with environmental pressures from the lack of moisture and nutrients in coastal soil and salty wind, P. thunbergii in coastal areas is expected to die massively. Although the causes of dead standing trees and poor tree vigor of P. thunbergii in the Hanbando coastal forest are complicated, poor management of adequate tree density in response to the growth of P. thunbergii is the primary cause. The secondary cause is external environmental pressures, including unfavorable soil conditions and salty and strong wind that obstruct the growth of P. thunbergii.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.1
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• pp.61-71
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• 2007

The main purpose of this study was to develop Automatic Measurement System for monitoring tree's vigor using Ubiquitous Sensor Network This study also focused on presenting an alternative for monitoring automatically tree's vigor due to Shigometer's limits. Application test of the system in comparison with Shigometer showed that the measurement values were not different to choose between the two, and battery lasted about 1,844 days in this system. To test the sensor network the possible transmission distance using the sensor network in maximum was 130m. Investigation and management expenses can be reduced and labor productivity will also be improved in the forest and street trees.

• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.302-306
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• 2016

There are various methods to evaluate tree vigor. Cambial electrical resistance represents tree vigor using the method of electrophysiological diagnosis. This study investigated the vigor of several tree species using Shigometer, and compared the differences among the species. The factors, such as foliation, trunk orientation and bark temperature, which affect electrical resistance were also investigated. The needle penetration into cambium was controlled to keep the depth consistent in order to minimize measurement error. Each of three trees were selected from Zelkova serrata, Ginkgo biloba, Metasequoia glyptostroboides, Pinus koraiensis, and Liriodendron tulipifera. The electrical resistances were measured at 60 and 120 cm height of the stem in 4 directions from March until May 2011. The soil conditions in surrounding areas and tree stress responses were also measured. The results were analyzed for the relationship between electrical resistance and the affecting factors. The electrical resistance showed a relatively higher level before foliation until mid-March. The values started to decline from April and recorded a minimal level on May 11. The changes of soil moisture, soil electric conductivity, and tree stress responses during the measurement period showed a similar trend to that of electrical resistance. The Pinus koraiensis, an evergreen conifer, showed few changes on the electrical resistance values during the measurement period. Zelkova serrata, Ginkgo biloba, and Metasequoia glyptostroboides showed the highest bark temperatures and lowest electrical resistances at their south-facing stem. Shigometer can provide measures simple to assess tree vigor in the fields, and to the management of trees.

• Journal of Forest and Environmental Science
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• v.16 no.1
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• pp.34-41
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• 2000

This study investigated tree vigor of damaged forest by Thecodiplosis japonensis Uchida et Inouye. In damaged forest by pine gall midge, the investigation result of damaged rate section (severe, moderate, light) indicated that severe stand showed higher value of electric resistance ($k{\Omega}$) than that of light stand, the investigation result of tree density section(crowed, middle, little) indicated that crowed stand showed higher value of electric resistance than that of little stand (the value of electric resistance at which low reading show high vigor tree and high reading low vigor tree). The crown width and DBH (diameter of breast height) of external factors showed lower value of electric resistance than that of small size. The results of comparative between Crown area and value of electric resistance in each stand were $13.4m^2$ in severe stand, $10.9m^2$ in moderate stand and $7.9m^2$ in light stand. Therefore, the tree which have big crown showed low value of electric resistance (below $15k{\Omega}$)that has high possible of survial.

• Journal of Korean Society of Forest Science
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• v.98 no.5
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• pp.584-592
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• 2009

The objective of this study was to examine the impact of pruning intensity on the vigor and cambial growth of the treated trees, and on the closure of pruning wounds for one year after pruning treatment. Two tree species, Pinus strobus and Acer palmatum, planted broadly in the urban forest of Korea were selected for the experiment. Intensity of pruning, which was estimated by proportion of removed branches, was categorized into five levels with about 10% intervals from lowest 8% up to 46%. Following parameters were examined; cambial electrical resistance (CER) and the cambial growth of trunk at 30 cm above the ground for the years before and after pruning, the cambial growth of stem at 1.5 cm above the branch bark ridge (BBR) of the pruned branch, and closure of pruning wound for one year after pruning. Tree vigor inferred from CER had a tendency to be weakened as pruning intensity increased in P. strobus, while that of A. palmatum was not affected. The trunk growth decreased significantly when the pruning intensity was higher than 30% in both species. The closure of individual pruning wound was related more to the cambial growth of stem at 1.5 cm above BBR than to the pruning intensity. Comparing the closure rate of pruning wound for one year, P. strobus with 72.1% was faster than A. palmatum with 39.3%, which corresponded with the rate of cambial growth of the two species.

• Korean Journal of Plant Tissue Culture
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• v.25 no.3
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• pp.159-163
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• 1998

In vitro shoot tip culture technique was established in pear (Pyrus pyrifolia 'Niitaka') as related to tree vigor, sampling time, and plant growth regulators and sucrose supplemented to medium. Shoot tips excised in June from the tree having medium-vigor developed good shoots. BA (1.0 and 2.0 mg/L) without NAA produced shoots suitable for proliferation, and NAA supplemented to medium resulted in poor shoot growth and excessive callus formation. BA of 2.0 mg/L combined with 0.01 mg/L NAA provided shoots suitable for rooting and sucrose of 30 g/L was recommended for proliferation medium. A fourth strength MS medium supplemented with 0.1 mg/L NAA produced plantlets in good quality of root number and root length.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.3
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• pp.56-65
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• 2009

This study was carried out to embody monitoring system of growing environments of fruit tree with Ubiquitous Sensor Network and to analyze various fruit qualities by the tree's vigor in the apple orchard located in Poonggi-eup, Yeongju-shi, Gyeongsangbukdo, Korea. The tree's vigor of apple trees was influenced to insolation, temperature, and humidity and it had influence on the weights, sugar contents and the quality(especially in mineral contents) of apples. The use of Ubiquitous Sensor Network will not only contribute to improve the quality of fruit by the offer of scientific fruit-cultivation method, but also to expand its application more and more.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.306-311
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• 2008

Proper tree vigor and crop load were determined for 'Fuji'/M.9 apple trees in high density planting system from 2001 to 2003. Leaf/fruit ratio was highly correlated to mean fruit weight (y=1.715x+205.02, $R^2=0.66^{**}$) and yield (y=-35.l56x+5963.7, $R^2=0.44^{**}$). In addition, there was a significant correlation between the number of leaves per tree and mean fruit weight. However, crop load did not affect tree growth, soluble solids content of fruit, and Hunter a value. To harvest the fruits heavier than 300 g without biennial bearing, it was appropriate to crop 55 to 64 fruits in a tree with 55 leaves per fruit of adult tree. The good indices for proper tree vigor could be 20 to 25 cm of mean shoot length and above 95% of shoot termination rate. Moreover, no secondary growth and 20 to 30% of spur formation could be the indices for highly productive tree vigor.

• Journal of Forest and Environmental Science
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• v.18 no.1
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• pp.45-52
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• 2001

This paper investigated external factors (height. crown width. diameter breath height, clear length) of tree and electric resistance ($k{\Omega}$) in damaged forest by Thecodiplosis japonensis Uchida et Inouye. The height. crown width and diameter breath height of tree external factors have high a coefficient of correlation. but clear length has not a coefficient of correlation. In relationship of electric resistance and external factor. big tree that height. crown width. diameter breath height has lower electric resistance value than that of small tree. (low electric resistance value is high tree vigor, high electric resistance value is low tree vigor)) Dead tree have smaller diameter breath height. crown width. higher clear length than survival tree in damaged forest by Thecodiplosis japonensis Uchida et Inouye. To investigation of relationship external factors according to electric resistance value. electric resistance value was divided three class (< $l4k{\Omega}$, possible of survival. $14{\sim}20k{\Omega}$, > $20k{\Omega}$, possible of dead). In lower class(< $l4k{\Omega}$), external factors have bigger which was height. crown width. diameter breath height and lower which was clear length than them of higher class ($14{\sim}20k{\Omega}$, > $20k{\Omega}$). Linear regression solutions of electric resistance and external factors were Y = -0.572 ${\times}$ Height - 1.163 ${\times}$ crown width - 0.242 ${\times}$ diameter breath height + 0.757 ${\times}$ clear length + 25.765. Regression solutions were significant in 5%.