• Journal of the Korean Institute of Landscape Architecture
• /
• v.35 no.3
• /
• pp.105-113
• /
• 2007

This study was conducted to analyze the effects of environmental factors such as soil moisture, light intensity, temperature and humidity on changes in cambial electrical resistance. To improve data quality, cambial electrical resistance was continuously measured at fixed points by using a data logger isolated from alternating current. The relationship between environmental factors and changes in cambial electrical resistance was also analyzed. The results are as follows: 1. Cambial electrical resistance is highly correlated to the temperature of the measured area(r=-0.934). Therefore, temperature compensation is needed to analyze the effects of other environmental factors on cambial electrical resistance changes. 2. If temperature is compensated for, the change of cambial electrical resistance is highly correlated to water vapor pressure(r=-0.836). 3. If temperature and humidity are compensated for, the change of cambial electrical resistance is highly correlated to intensity of light(r=-0.738). 4. Diurnal deviation of soil water potential is not more significantly related than the change of cambial electrical resistance. However, in the long-term, soil water potential and cambial electrical resistance are highly correlated(r=-0.831). This indicates that soil moisture significantly influences the long-term change of cambial electrical resistance.

• Korean Journal of Environment and Ecology
• /
• v.16 no.1
• /
• pp.46-54
• /
• 2002

This study was conducted to diagnose the health of street trees with physiological characters, and to figure out the relation of physiological characters and cambial electrical resistances. Ginkgo biloba, Prunes serrulata and Salix koreensis were chosen in the Cheonan City. Soils under trees were collected to analyze dehydrogenase activities, and chlorophyll content, nitrate reductase and superoxide dismutase activities were analyzed from leaves sampled at the edge of crown in July. Cambial electrical resistances were measured in May, July and September, Soils with low dehydrogenase activity reflected the level of pollution. Chlorophyll content was the lowest in the leaves of P. serrulata at the Dongseo-street. Nitrate reductase activity of Ginkgo biloba was higher than P. serruluta and Satix koreensis. Nitrate reductase activity showed higher activity in the city than control(Independence Hall and Yonam College), but superoxide dismutase activity in the city lower than control. P. serruzatu in the Dongseo-street that cambial electrical resistance increase continuously during the growing season, showed the loss of vitality Cambial electrical resistance was negatively or positively correlated with nitrate reductase($r^2$=-0.566) and superoxide dismutase activity($r^2$=0.579). It was concluded that cambial electrical resistance might be suitable for diagnosing the tree health.

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

• Journal of the Korean Institute of Landscape Architecture
• /
• v.22 no.4
• /
• pp.75-80
• /
• 1995

It is important to estimate the possibility of recovery in physiologically damaged woody plant. It is suggested that C.E.R(cambial electrical resistance) might be a useful method to predict the permanent wilting point. D/A and A/D converter can be used to measure the C.E.R and it took only 10-20 msec for a measurement and the values were stable during this study. A computer could be used for the continual measurement of C.E.R. There were very big daily changes of C.E.R. was changed according to the changes of indoor temperature, but the phase was slightly different. It is reasoned that daily changes in C.E.R. is induced by the changes of water potential and cambial thickness. It was difficult to detect the changes of C.E.R. caused by changes in soil moisture under high soil water potential. Under low soil water potential, the changes in soil moisture under high soil water potential. Under low soil water potential, the changes of C.E.R. can be detected. After wilting, C.E.R. is increased very rapidly. When C.E.R. is not decreased by watering, it will be permanent wilting point. But it takes several days to confirm the permanent wilting point. To predict the possibility of recovery from wilting, the values of C.E.R. have no meaning. But the changes of C.E.R. are significant. Therefore we can predict the permant wilting point in woody plant by monitoring the change of C.E.R. by the computer.

• Ecology and Resilient Infrastructure
• /
• v.3 no.4
• /
• pp.302-306
• /
• 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 Environmental Science International
• /
• v.21 no.11
• /
• pp.1307-1320
• /
• 2012

The purpose of this paper is to provide information on planting construction for healthy plant growth. To achieve this purpose, this study analyzed the planting type, planting density, withering rate, soil characteristics, and cambium electrical resistance (CER) of withered trees in an apartment complex with a high withering rate. The major plant groups examined consisted of native broad-leaved tree species (39.3%), native narrow-leaved tree species (24.2%), and native broad-leaved - exotic narrow-leaved tree species (16.4%). The planting density of the green area, where trees were planted from 0.0 to 0.3 trees per unit area, was measured as 98.4%. Withered trees were found in 19 of the 20 planted species, and the withering rate was 41.8% (610 withered/1,461 planted). Withering rates for tree species were measured as follows: Sophora japonica and Salix babylonica (100.0%), Magmolia denudata (84.3%), Lindera obtusiloba (74.7%), cornus kousa (69.3%), acer triflorum (69.2%), diospyros kaki (66.7%), Prunus yedoensis (62.8%), Acer palmatum (52.6%), Prunus armeniaca (51.1%), Chaenomeles sinensis (43.7%), Ginkgo biloba (40.9%), Zelkova serrata (31.0%), Cornus officinalis (28.6%), Taxus cuspidata (25.6%), Pinus densiflora (21.4%), Pinus parviflora (15.2%), Pinus strobus (14.6%), and Abies holophylla (10.3%). Soil chemical analyses for 18 samples revealed that as the withering rate increased, the following occurred: (a) the ratio of silt and clay in soil increased; (b) the soil pH, organic matter rate, nitrogen, available phosphorus, and cation exchange capacity (CEC) in samples were graded as "inadequate," based on the plant grading evaluation; and (c) the NaCl and cation exchange capacity were evaluated as "somewhat satisfactory." The measurement of CER for withering rate shows electrical resistance for higher withering rate are higher, which could predict that a tree will not grow well.

• Journal of Korean Society of Forest Science
• /
• v.98 no.5
• /
• pp.618-629
• /
• 2009

The objective of this study was to examine the impact of pruning (P treatment) and transplanting (T treatment) of Acer palmatum on cambial growth and compartmentalization of pruning wounds for one year after treatments. Changes of cambial electrical resistance (CER), sizes of pruning wounds, cambial growth of trunks and stems near the wounds, and total phenols at branch unions during the period were examined using a total of 49 trees. After harvesting, areas of discolored wood behind the wounds, relative proportions of extractives, holocellulose and lignin at branch unions were also determined. CER and the cambial growth of trunk at 30 cm above the ground (TGR) were inversely correlated, and differences of CER and TGR among three treatments were significant. TGRs of control, P treatment and P+T treatment after the treatments were 112.2%, 72.4% and 52.5% of the annual growth for the year before the treatments, respectively. The cambial growth rate of stem (SGR) at 1.5 cm above the branch bark ridge and the closure rate of pruning wound (WCR) for one year after treatments were positively correlated, and WCR of P treatment of 39.8% was significantly higher than that of P+T treatment of 31.8%. Wounds of P+T treatment formed greater discolored area per unit area of pruning wound (D/W Ratio) than those of P treatment significantly. Lower WCR and higher D/W Ratio of P+T treatment suggested less ability of compartmentalizing the wounds than P treatment. Total phenols at branch core of pruning wound for both treatments heightened a month after treatment, and then lowered. The contents at below core of the wound were higher than those at control ones continuously, while they became similar each other at above core. Relatively high phenol contents of the extractives at P+T treatment implied that trees with P+T treatment allocated more energy to compartmentalize their wounds. Holocellulose and lignin contents at the branch core of treated branch unions of both treatments were lower and higher, respectively, than at the same part of the union with living branch, as results of the tree reaction to protection from wounding and microbial invasion.

• Korean Journal of Environment and Ecology
• /
• v.30 no.3
• /
• pp.415-422
• /
• 2016

This study measured the vitality of Pinus densiflora and Ginko biloba and analyzed the differences of vitality levels among trees based on artificial management. Research has shown that the mean value of cambial electrical resistance (CER) on Pinus densiflora was $14.9K{\Omega}$(between $8.5{\sim}37.5K{\Omega}$), and for Ginko biloba it was $13.5K{\Omega}$ (between 6.4 and $40.5K{\Omega}$). For the purpose of artificial management, over 50% of trees were covered up with soil and about 40% of trees were not protected by fence to enable growth spaces. It was seen that the CER of trees covered up with soil was significantly higher than that of trees which were not covered up with soil. These results indicate that it is necessary to remove the soil covering for effective management of monumental trees.

• Journal of People, Plants, and Environment
• /
• v.24 no.1
• /
• pp.85-94
• /
• 2021

Background and objective: This study examined, compared, and analyzed the tree vitality of the trees growing on the artificial ground of Seoullo 7017 that transformed the overpass that was to be demolished into a "sky garden" using portable tree pots. Methods: Based on the summer season when the metabolic activity of plants is most active, this study measured the cambial electrical resistance in four directions(east, west, south and north), using the Shigometer (model OZ-93, Osmose) and compared the location and analysis of pots according to their means and standard errors. Results: Meanwhile, according to the analysis, vitality was relatively superior in pots with a big diameter, trees planted individually than in groups, trees of the ramp section rather than the bridge section, and in the southwest direction of the cambium. Conclusion: This study revealed the improper condition of the planting plan and implementation on the site, where various species of trees are displayed in a poor environment. Despite the significant assessment of the vitality of various trees introduced within Seoullo 7017 for the first time, this study is limited in that the data used were measured only once in summer. In this regard, it raised the need for continuous interest in and monitoring of a special plant environment and development of proper maintenance and management techniques, along with follow-up research on seasonal and temperature conditions, soil moisture and root development conditions to supplement this research.

• Journal of Korean Society of Forest Science
• /
• v.86 no.4
• /
• pp.415-421
• /
• 1997

The objectives of this study were to obtain standardized basic data on cambial electrical resistance (CER) of ornamental trees to be used for estimation of tree vigor and to compare CER between shrubs, deciduous, and coniferous trees in relation to bud opening, flowering, and growth cessation. Eighty healthy trees with four trees each for twenty ornamental tree species growing at an university campus in Suwon were selected and their CER was measured using a Shigometer every week from March to May, once a month from June to October and every two weeks in November, 1996. The CER of all tree species was high in March, started to decrease in April, maintained minimum in May through August, began to increase in September, and returned in November to the similar high level to March. Among the 20 species, Metasequoia glyptostroboides showed the lowest($5.5k{\Omega}$) annual average CER, while Cercis chinensis and Ligustrum obtusifolium had the highest($22.7k{\Omega}$, $22.9k{\Omega}$) annual average CER. The lowest CER($2.4k{\Omega}$) in summer(June through August) was obtained from Wisteria floribunda, second lowest($2.5k{\Omega}$) from Metasequoia glyptostroboides, the highest CER($46.8k{\Omega}$) during dormant season from Euonymus japonica, and second highest($45.0k{\Omega}$) obtained from Ligustrum obtusifolium. The CER of most species, particularly shrub species, started to decrease with bud opening, and many species, particularly shrubs and deciduous trees with large amount of flowers, showed sharp decrease with flowering. When CER was compared between shrubs and trees, shrubs showed higher average CER than trees, and seasonal difference in CER of evergreen species was smaller than that of deciduous species. It is interesting to note that the deciduous Metasequoia glyptostroboides had the lowest annual average CER.