• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.175-181
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• 2014

This study was conducted to evaluate stand density-specific and generalized allometric equations, and biomass expansion factors (BEFs) for two stand densities (high density of 47-year-old: $667tree{\cdot}ha^{-1}$; low density of 49-year-old: $267tree{\cdot}ha^{-1}$) of Cryptomeria japonica plantations in Namhae-gun, located in the southern Korea. Biomass in each tree component, i.e. foliage, branch, and stem, was quantified by destructive tree harvesting. Allometric regression equations of each tree component were significant (P<0.05) with diameter at breast height (DBH) accounting for 80-96% of the variation except for branch biomass in high density or foliage and cone biomass in low density. Generalized allometric equations can be used to estimate the biomass of C. japonica plantations because the slopes of allometric equations were not significantly different by the stand density. The biomass expansion factors (BEFs) were significantly lower in the high stand density (1.33) than in the low stand density (1.50). The results indicate that BEFs were affected by different stand density, while allometric equations were little related to the stand density.

• The Korean Journal of Soil Zoology
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• v.5 no.2
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• pp.47-62
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• 2000

This study investigated the effect of soil animals at forest fire area, and it carried out the mountain located at Jundae Ri, Houeng-chen Myen, Ha-dong Gun, Kyoung-Nam Province, southern part of Korea, where burned out about 50 hectars on April 11, 1997. Vegetation of the examined area absolutely dominated with the pines of 7-14 cm in diameter and 20 to 30 years old and the rest were covered with mixed forest with a shrub such as the oak (Quereus mongolia Fisch, Quereus variabilis BI, Quereus dentana Thunb), snowbell(Styrax japonica, S, et, z), lacquer tree (Rhus trichocarpa Mig), azalea (Rhododendron mucronulatum Turcz), etc. And there were simple area organized as a herbaceous plant, and the burnt area was poor experimental sites, where litter layer and herbaceous plant disappeard due to fire, and the unburnt area was rich in surface plant, dead leaves, twigs, etc. But the ground cover vegetations were poor in the unburnt area. The distribution of each animal groups, the seasonal fluctuation in population density, the biomass of meso$.$macroarthropods and the relationship between soil animal and some environmental factors were investigated and analyzed at each experimental area. The result are summarized as follow: 1. Identificated 257,087 individuals of soil microarthropods were classified into 7 classes and 24 orders of Arachinida, Insecta, Chilopoda, Symphyla, Diplopoda, Isopoda and Oligochaeta., and identified 8,006 individuals of the total meso$.$macroarthropods were classified into 7 classes and 20 orders of Arachinida, Insecta, Chilopoda, Symphyla, Diplopoda, Isopoda and Oligochaeta. 2. Among the total soil microarthropods, Arachinida formed 70.9%, followed by Insecta for 28.4% and among the total meso$.$macroarthropod , Insecta formed 57.6%, followed by Chilopoda for 23.8%.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.363-367
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• 2008

Abamectin 1.8% EC and emamectin benzoate 2.15% were evaluated the simultaneous control effect of both insect pests on black pine (Pinus thunbergii) against Thecodiplosis japonensis and Matsucoccus thunbergianae. Abamectin 1.8% EC was highly effective against T. japonensis and M thunbergianae, however, emamectin benzoate was highly effective against only M. thunbergianae when abamectin and emamectin benzoate were applied through trunk injection against T. japonensis and M thunbergianae at the rate of 1 ml per cm in diameter of breast height. The rate of gall formation of T. japonensis was 0% at the applied year, but 85% at the following year. However, the rate of gall formation was over 90% at the treatment of emamectin benzoate showing no difference compared with control. Abamectin 1.8% EC and emamectin benzoate 2.15% showed high control efficacy representing 89.1% and 91.4% against M. thunbergiana, respectively.

• Journal of the Korean Wood Science and Technology
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• v.43 no.3
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• pp.320-326
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• 2015

Mechanical properties of woods are easily affected by the differences of site environment such as soil and climate changes. In this study, the relationship between mechanical properties and growth factors for Cryptomeria japonica stands in Jeollanam-do Province, Gyeongsangnam-do Province and Je-ju island was analyzed. From these plot data, bending strength, compressive strength, and shear strength were analyzed by Duncan's new multiple range test. The results of Duncan's new multiple range test analysis indicated that bending strength, compression strength, and shear strength were positively related to tree mean height, and stem number per ha, respectively, while they were inversely proportional to DBH (diameter at breast height), elevation, and soil drainage. As a result of this study, there are high correlations between mechanical properties of wood and stand characteristics of Cryptomeria japonica by the region, this findings are very useful to apply the silvicultural treatment system to produce high quality timber as a basic data on this species (distributed in southern region of Korea).

• Korean Journal of Plant Resources
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• v.16 no.2
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• pp.99-108
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• 2003

This study was carried out to make a standard criteria for protection and maintenance of the big and old trees in Ansung city, Kyonggi Prvince. There have been found 6 vegetative species cultivated in this area, which are Zelkova serrata, Gingko biloba, Kalopanax pictus, Pyrus ussuriensis var. macrostipes, Pyrus ussuriensis var. acidula, Pinus densiflora, etc. The Zelkova serrata tree is the major species among them and about 73.5％ in the population of the big and old trees in this area. The DBH (diameter at brest height) of them is 1.5-1.9m in 29.4% of whole population and the tree height is 10-l4m in 47.1%. The estimate age of 7 trees is more than 500 years old and they were 20.6％ of the whole population. Interesting point is that about 64.7％ of these trees in this area have own succeed story in terms of folk religion, object of worship, taboo, legend or secret. This study has also revealed that many fowls, small animals and epiphyte inhabited with the big and old trees have been found. However, 97.1％ of them are in danger from the plant disease and noxious insects or cutting damage of branches, but no management has been taken. More over, 85.3％ of the whole investigated big and old trees have been in the poor condition for percolation or aeration because the area around them has been payed with asphalt or concrete.

• Korean Journal of Environment and Ecology
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• v.28 no.4
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• pp.385-392
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• 2014

Quercus gilva Blume is an evergreen-leaved tree that belongs to Facaceae and grows in tropical and warm-temperate regions, such as Japan, Taiwan, China and Korea. This study was carried out to analyze the distribution and growth characteristics of Q. gilva in the native range. In Korea, this species was distributed in Jeju Island between 80 and 350 meter above sea level, and mainly in the south-western regions of the island from 100 to 200 meter above sea level. The average height of Q. gilva was $9.8{\pm}1.9$ meter, with most trees 9 and 12 meter tall. The average diameter at breast height was $22.6{\pm}6.8$ centimeter, with the majority between 20 and 30 centimeter. Several coppice shoots ($3.8{\pm}2.1$ pieces) were formed from stumps and inferred by frequent cuttings for use. Almost Q. gilva individuals(96.2%) were covered with kinds of vines(18 species), and evergreen Trachelospermim asiaticum (Siebold et Zucc.) Nakai was major species. The analysis of damage of vines revealed that the most dead branches were found with 9 to 12 meter height of Q. gilva, and the more vines attached, the larger damage to Q. gilva individuals. A continuous monitoring and investigation would be required to preserve this species in their habitats.

• Journal of Korean Society of Forest Science
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• v.103 no.4
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• pp.613-621
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• 2014

This study was conducted to estimate the changes of stand diversity before and after applying three different silvicultural treatments such as selection cutting system, two-storied system, and shelterwood system. Data were collected in the natural deciduous forests in Pyungchang of Gangwon Province, Korea. Nine permanent sampling plots of 0.09 ha were established in the forests and the each of silvicultural treatments was applied to three sampling plots, respectively. Some tree variables were measured in each stand before and after the silvicultural treatments were applied. With these data, stand attributes were estimated in each stand before and after the silvicultural treatments. In this study, two different indices related to each of stand diversity indices such as contagion, DBH-difference, height-difference, and mingling were estimated and compared to analyze the differences of stand diversity among the stands before and after silvicultural treatments. As a result, total eight stand diversity indices were used to analyze the differences among structures of stands managed by three different silvicultural treatments. Duncan's multiple range test and t-test were then employed to statistically analyze the difference of stand diversity among the stands. The results revealed that stand structures seem to be improved after applying the silvicultural treatments. There are significant differences in the stand diversity indices between before and after silvicultural treatments for each stand. According to the evaluation of stand diversity indices, it was confirmed that spatial structure of the stands was improved by applying the silvicultural treatments.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.297-304
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• 2012

The objective of this study was to estimate the changes of stand structure before and after applying the three different silvicultural treatments such as selection cutting system, two-storied system, and shelterwood system. This study has been conducted in the natural deciduous forests in Pyungchang of Gangwon Province, Korea. Three permanent sampling plots of 0.09 ha were established in the forests and the three silvicultural treatments were applied in 2008. For this study, some tree variables were measured in each stand before and after the silvicultural treatments were applied. With these data, stand attributes were estimated in each stand before and after the silvicultural treatments. In this study, four stand structure indices were used to analyze the differences among structures of stands managed by three different silvicultural treatments. Contagion index, DBH-difference index, height-difference index, and mingling index were estimated and compared to analyze the differences of stand structures among the stands before and after silvicultural treatments. Duncan's multiple range test and t-test were then employed to statistically analyze the difference of stand structure among the stands. The results revealed that all of the stand structure indices seem to be increased after applying the silvicultural treatments. There are significant differences in the stand structure indices between before and after silvicultural treatments for each stand. According to the evaluation of stand structure indices, it was confirmed that spatial structure of the stands was improved by applying the silvicultural treatments. For attaining the specific goal of each stand types acquired by different silvicultural treatments, the frequencies and amounts of additional practices should be decided based on the changes of stand structure as time passed.

• Journal of Korean Society of Forest Science
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• v.82 no.1
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• pp.12-16
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• 1993

Post-harvest trunk injection of oxytetracycline-HCl(OTC) was attempted for the control of jujube witches'-broom. Diseased jujube(Zizyphus jujuba) trees with 9 to 16cm trunk diameters were treated with OTC ranged from 2g to 6g according to the size of trunk diameter. OTC dissolved in 0.51 or 1.01 of water was transfused into diseased trees by gravity flow injection during September and October. All these OTC concentrations prevented symptom development for two growing seasons and restored previously severely diseased trees to normal conditions. There was no differences in control effect between 0.51 and 1.01 OTC solutions. With these high OTC concentrations, no phytotoxicity was observed in the new leaves of the following year. Mycoplasma -like organism (MLO)-specific fluorescence was absent in the phloem of recovered tissue when examined by fluorescence microscopy using DAPI(4'-6-diamidino-2-phenylindole.2HCl) staining, indicating the disappearance of MLO by the action of OTC.

• Korean journal of applied entomology
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• v.57 no.3
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• pp.143-149
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• 2018

The black pine bast scale (BPBS), Matsucoccus thunbergianae (Homoptera: Margarodidae), is one of the most serious insect pests of Japanese black pine (Pinus thunbergiana) in Korea. The density of BPBS varies by tree, branch, and location, making it difficult to monitor them. This study investigated to find a monitoring method for distribution and occurrence of BPBS on Japanese black pine using the yellow sticky trap. The density of male BPBS on sticky trap and nymphs from the branch of Japanese black pine was highly correlated in various surveyed sites. The number of male BPBS that attracted to the yellow sticky traps was higher in upper crown than the lower crown of P. thunbergiana but this was not statistically significant. The density of BPBS nymphs increases with the increase of the diameter of the branch, but the differences were not significant from 1 to 2.5 cm. BPBS was highly distributed in bottom-faced branch than the upper-faced branch of P. thunbergiana. Therefore, we suggest, the yellow sticky trap for the monitoring of BPBS and when examining the nymph density in branch, it is recommended that the bottom-faced branch of the 2-2.5 cm diameter branch be examined.