• Journal of the Korea Furniture Society
• /
• v.18 no.4
• /
• pp.275-281
• /
• 2007

This study was carried out to know bending process property of bentwood by treatment methods such as microwave and ammonia solution treatment. Bentwood processing was operated on bending-jig form with 60mm and 100mm radius of curvature (ROC). The species was used to Korean red pine (Pinus densiflora). No significant difference was shown in bentwood processing method on ROC. In treatment method, ammonia solution treatment for bentwood was better in dimensional stability and working ability than that of microwave treatment. However, bentwood stress was reduced with ammonia solution treatment. Color of bentwood surface appearance has a dark tendency in ammonia solution treatment. But it seems to beautiful effect of apparent annual ring is rising esthetically by ammonia solution treatment. To utilize wood as a exterior material for living amenity, it has to be closely examined from various angles including surface property, degree of swelling and shrinkage, drying state, retaining strength, durability, safety, and insect damage.

• Journal of the Korean Chemical Society
• /
• v.15 no.6
• /
• pp.370-377
• /
• 1971

The Carbon-14 content in surface air at Seoul, Korea, was measured from February 1970 to August 1971 and a Larix Leptolepis, Gordon tree (Ip-Gal Namu) grown at Kwang-Nung, Kyunggi-Do, Korea, having 37 growth rings, was assayde for $^{14}C$. From the results of the surface air study, it was calculated that during the above period the inventory of excess $^{14}C$ in the atmosphere decreased with a half-time of 4.6 years. The overall yearly decrease was also checked. The tree-ring study showed that the tree's atmosphere was affected by $^{14}C$ from nuclear tests after 1956. In one study, atmospheric $CO^2$ samples were collected bi-monthly by the absorption of $CO^2$ in alkaline hydroxide solution. In the other, 5 year annual growth rings were assayed for radiocarbon. For the radioactivity measurement, carbon atoms in samples were converted to carbon atoms of benzene. The resulting benzene was taken as primary solvent for liquid scintillation counting.

• The Korean Journal of Ecology
• /
• v.21 no.2
• /
• pp.125-131
• /
• 1998

Histological damage and growth inhibition of Pinus densiflora were analysed in different areas around the Metropolitan area of Seoul urban (heavily polluted), suburban (lightly polluted), and rural(unpolluted) areas. Soil properties of each area were also investigated. Contact angles of water droplet on needle leaves growing in polluted areas were lower than that in unpolluted area. Transpiration rates of needle leaves growing in polluted areas were more rapid than that in unpolluted area. These results represented that needle leaves growing in polluted areas were more susceptible to water deficit than that growing in unpolluted area was. Growths of annual ring of Pinus densiflora growing in polluted areas were lower than that in unpolluted area. On the other hand, soil pH in polluted areas was lower than that in unpolluted area. That is, the former was more acidified than that the latter was. Ca and Mg contents in polluted areas were lower than that in unpolluted area, while Al contents in polluted areas were higher than that in unpolluted area. These soil properties revealed that the effects of acid precipitates in urban and suburban areas were severer than that in rural area.

• The Korean Journal of Quaternary Research
• /
• v.6 no.1
• /
• pp.21-32
• /
• 1992

The paleoclimate of the Chungbu Mountainous Region, Mts. Seorak and Sobaek, was estimated by means of dendroclimatic methodology, The annual growth value of tree-rings is deeply interrelated with the mean temperature of April-May and July-August. The mean temperature of April-May of the reconstruction period(1635-1911), observation period(1912-1989), and the whole period(1635-1989) is 13.58$^{\circ}C$, 13.69$^{\circ}C$, and 13.6$0^{\circ}C$, respectively. That of July-August is $24.50^{\circ}C$, $24.62^{\circ}C$, and $24.58^{\circ}C$ respectively. The reconstructed mean temperature data for April-May and for July-August reveal 13.2 and 12.9 year cycles.

• Korean Journal of Ichthyology
• /
• v.25 no.1
• /
• pp.25-32
• /
• 2013

We studied the age and growth of striped beakperch (Oplegnathus fasciatus) in the Jeju marine ranching area using a total of 423 otoliths from August 2009 to August 2010. The surface reading method, which was etched with 5% HCl, was the best method to read ages of this fish. The monthly mean fork length ranged from 20.9 cm to 27.7 cm in the Jeju marine ranching area during from August 2009 to August 2010. The annual ring was formed in July to September once a year. Fish were principally composed of 3 to 5 years old and the oldest was 12 years old. The von Bertalanffy growth parameters of this species, which were estimated from a non-linear regression, were $L_{\infty}$=48.20 cm, $t_0$=-1.031yr, and K=0.123/yr.

• Journal of the Korean Wood Science and Technology
• /
• v.26 no.4
• /
• pp.20-25
• /
• 1998

Radial variation of crystalline state in a stem of Chamaecyparis obtusa E. was examined by x-ray diffraction analyses. Relative crystallinity and degree of crystallite orientation showed significant differences between juvenile and adult wood. That is, Relative crystallinity increased with increasing the age from pith to about 20th annual ring, after which it reached a more or less constant value. On the other hand, degree of crystallite orientation decreased outward from pith to about 10 years and presented almost a constant value thereafter. Crystal width by Scherrer's equation did not show any significant differences between juvenile and adult wood. Therefore, it was considered that crystallinity index and degree of crystallite orientation by x-ray diffraction method could be used for evaluating wood quality.

• Journal of the Korean Wood Science and Technology
• /
• v.34 no.1
• /
• pp.52-60
• /
• 2006

This study investigated how wood properties (i.e., annual rings, sapwood, heartwood, and cracks) might affect preservative treatment in Japanese larch (Larix leptolepis) round-wood product. We specially focused on small-diameter (~10 cm diameter) wood that is commercially sold in market. Among 100 wood samples, the groups of sample with 13~16, 17~20 annual rings represented 33 and 27 in each frequency, while 2~3 and 4~5 mm annual ring width accounted for 72 and 68 in frequency. More than a half (54%) of wood samples contained a mix of heartwood and sapwood in its surface. The rest (46%) had only heartwood exposed in the wood surface. A wide range of checks were showed in the wood samples, but the highest frequency was observed in samples with 1~6 surface (1~14 mm in size) checks and 1~4 end-grain (8~14 mm in size) checks in each round-wood sample. Pressure treatment resulted in a wide range of penetration of ACQ (Alkaline Copper Quat) into the wood, showing $4.3{\pm}4.19mm$ penetration in the wood samples contained a mix of heartwood and sapwood in its surface. However preservative treatment was much less effective for the heartwood only wood samples, ranging average 1.3 mm with ACQ and 1.1 mm with CCA (Chromated Copper Arsenate). These penetration results shown in heartwood samples did not meet the penetration standard that is required for H3 by the Korean Forest Service in relation to wood preservation treatment. These low penetration results were not significantly improved even if we incised wood samples to improve treatment effect, showing only small increase of 0.7 mm with ACQ and 0.6 mm with CCA. When preservative treatment was tested with heartwood, penetration of preservatives decrease with increase of annual rings per a cross-section area (r=0.5345). We also found that the length and number of check had no effect on preservative treatment, showing r=0.1301 and r=0.1802, respectively.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.18 no.3
• /
• pp.109-119
• /
• 2016

This study was conducted to analyze the effect of yearly changes in growing degree days (GDD) on the potential distribution and growth of Quercus mongolica in Korea. Annual tree-ring growth data of Quercus mongolica collected by the $5^{th}$ National Forest Inventory were first organized to identify the range of current distribution for the species. Yearly GDD was calculated based on daily mean temperature data from 1951 to 2010 for counties with current distribution of Q. monglica. When tree-ring growth data were analyzed through cluster analysis based on similarity of climatic conditions, seven clusters were identified. Yearly GDD based on daily mean temperature data of each county were calculated for each of the cluster to predict the change of potential distribution. Temperature effect indices were estimated to predict the effect of GDD on the growth patterns. In addition, RCP 4.5 and RCP 8.5 of climate change scenarios were adopted to estimate yearly GDD and temperature effect indices from 2011 to 2100. The results indicate that the areas with low latitude and elevation exceed the upper threshold of GDD for the species due to the increase of mean temperature with climate change. It was also predicted that the steep increase of temperature will have negative influences on tree-ring growth, and will move the potential distribution of the species to areas with higher latitude or higher elevation, especially after the year of 2050. The results of this study are expected to provide valuable information necessary for estimating local growth characteristics and for predicting changes in the potential distribution of Q. mongolica caused by climate change.

• Korean Journal of Environment and Ecology
• /
• v.26 no.3
• /
• pp.394-405
• /
• 2012

The aim of this study was to propose methods to transplant for the ecosystem damage borrow pits. The research site is Junggun-dong Gwangyang-si Jeollanam-do. The total area of the site is approximately $199,026m^2$, but the area damaged by exploitation of soil and rocks is about $84,200m^2$. This signals the transplanting method to solve the problems of ecological destruction. The research will focus on the areas either which are evaluated as damaged or in which the development is inevitable. Therefore, this study will investigate the vegetation structure and their evolution, topological and soil character, and annual ring structure; in the end, the study will propose compensating and restoring options. This study proposed the selection of trees and their planting methods by using the models of the community transplantation(Quercus mongolica trees) and the tree transplantation(Pinus thunbergii trees). The study set out plans that will attempt to restore the Quercus mongolica forests and 89 Quercus mongolica trees of the canopy layer trees, 153 middle layer trees, and 661 shrubs are suitable. The tree transplantation utilized the existing Pinus thunbergii trees. The number of transplantation is 2,648. The total area of the transplantation topsoil is calculated to be $15,353m^3$. These study results must be contributed to reduce a damaged ecosystems and compensated damaged ecosystems for solving the problem of damaged borrow pits.

• Journal of Korean Society of Forest Science
• /
• v.109 no.1
• /
• pp.62-71
• /
• 2020

With the aim of restoring slow-moving landslide areas, this study collected fundamental data from tree-ring analysis of curved trees in these areas. We collected both upper and lower stem disks to measure the azimuth angles of six trees with growth curvature caused by tension cracks. Additionally, we analyzed various factors in the slow moving landslide area. The geological strata and main constitutive rocks in the study area were anorthosite-formed in the Precambrian period; moreover, there were no intrusive rocks, other geological strata, geological folds, or faults. The talus with weathered rocks was distributed in the upper zone of the slow-moving landslide area. According to annual-ring analysis of curved trees and terrain analysis by satellite imagery, slow-moving landslide occurred from the top to the bottom end of the slope between 1999 and 2011. There was a significant relationship (P < 0.01) between the azimuth angle of cracks caused by the slow-moving landslide and the angle of the curved trees. These results suggest that the occurrence of slow-moving landslides could be confirmed through analysis of annual-rings of curved trees, underground water levels, and terrain (by satellite imagery).