• Journal of the Korea Furniture Society
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• v.27 no.2
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• pp.91-95
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• 2016

This study was conducted to investigate the relationship between water absorption (or hygroscopic property) and growth rate of rubra oak (Quercus rubra) from 5 different origins of seed (Carleton, Simcoe, Chatham, Bancroft, Unknown). Water absorption at cross section of Quercus rubra was $0.43{\sim}0.92g/cm^2$ and the property was not related with growth rate. Overall equilibrium moisture content of rubra oak were 11.35~11.56% and 15.15~15.83% at $40^{\circ}C$ with 75% and 90% relative humidities, respectively. There was no relationship between growth rate and moisture content(hygroscopy) in rubra oak. Based on the results, Rubra oak can be classified as a low hygroscopic wood grade, and thus might be a good raw material for furniture productions owing to its superior dimensional stability.

• The Korean Journal of Mycology
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• v.50 no.2
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• pp.137-141
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• 2022

In Korea, powdery mildew has been observed on Quercus rubra, commonly called the northern red oak tree. Based on its morphological and molecular phylogenetic analyses, the fungal agent was identified as Erysiphe quercicola, but it was distinct from the other four Erysiphe species, specialized to Quercus species. This is the first confirmed report on the identity of powdery mildew found on Q. rubra in Korea. This finding can help understand the host expansion of E. quercicola and the biodiversity of powdery mildew on Quercus species.

• Journal of the Korean Wood Science and Technology
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• v.43 no.4
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• pp.421-428
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• 2015

This study was carried out to investigate the relationship between anatomical characteristics and growth rate of Quercus rubra from different origins of seed. Anatomical characteristics showed that all Quercus rubra species were ring-porous woods with 1~3 layers of large pores in earlywood, but the latewood had small pores oriented in radial direction. There were slight differences in libriform fiber length and vessel element diameter in the earlywood among different provenance origins of seeds. In growth rate, the libriform fiber length and vessel element diameter was negative correlation in the earlywood, but not correlative in the latewood, and vessel element length was not correlative in the early and latewood, Volumetric composition of libriform fiber and ray in latewood was higher than those in ear lywood, and a higher composition of vessel element was observed in earlywood. Ray height was the range of from 11 to 15 cells.

• The Korean Journal of Ecology
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• v.18 no.2
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• pp.219-230
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• 1995

Although many studies of nutrient cycling in forest ecosystems have reported that clearcutting creates increased organic matter decomposition and nitrogen (N) mineralization in soils, little is known about the change of these factors following various levels of canopy removal. A series of experimental plots with four levels of canopy cover, i.e., clearcut, 25％, 75％, and uncut, was established in northern red oak (Quercus rubra L.) stands in northern Lover Michigan, U.S.A. I examined decomposition of cellulose filter papers and N mineralization using an in situ soil incubation technique in the top 15cm of mineral soil during the second growing season (1992, May-October) following stand manipulation. Mass loss from cellulose filter papers was more rapid in the canopy removal treatments than in the uncut treatment. similarly, net N mineralization was significantly greater in the canopy removal treatments than in the uncut treatment. There was no significant difference in net N mineralization rates among the three levels of canopy removal. Net N mineralization for the growing season was 58 kg/ha for the clearcut, 54 kg/ha for the 25％ canopy cover, 51 kg/ha for the 75％ canopy cover, and 22 kg/ha for the uncut treatment. These results indicated that even only small amounts of canopy removal (leaving 75％ canopy cover) let to substantial increases of cellulose decomposition and the amount of available soil nitrogen.

• Journal of Korean Society of Forest Science
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• v.84 no.2
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• pp.198-206
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• 1995

The objective of this study was to determine the rate of nitrogen mineralization at clearcut and uncut in oak(Quercus rubra L.) and pine(Pinus resinosa Ait.) stands. The study sites were located in northern Lower Michigan, U.S.A. Nitrogen mineralization rates in the top 15cm of mineral soil were examined during the 1991 and 1992 growing seasons(May-October) using an in situ buried tag technique. diet nitrogen mineralization in oak stands over the course of both growing seasons was 67kg/ha in the clearcut and 30kg/ha in the uncut stands. In contrast, net nitrogen mineralization in pine stands was 27kg/ha and 13kg/ha for the same treatments. Total net nitrogen mineralization rates were always higher in oak stands than in pine stands. Extractable $NO_3^-$ before and after one month soil incubation in both oak and pine stands was generally not detectable in the uncut stands, but in the pine clearcut treatment(nitrification over the course of both growing seasons : 3.3kg/ha). The results indicated that : 1) substantial increases in the amount of available soil nitrogen occurred following clearcuts in both stands : and 2) the loin rates of nitrification may be an important mechanism for retention of nitrogen in both oak and pine stands.

• Journal of the Korean Wood Science and Technology
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• v.42 no.3
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• pp.327-338
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• 2014

Relationship between growth rate and wood quality was investigated by physical and mechanical properties with Quercus rubra (24 years old) from five different origin of apricot. In greenwood moisture content, sapwood had higher moisture content than heartwood, and there was difference among different origin of apricot. There were different specific gravity of wood among different origin of apricot. Compared with higher growth rate with higher specific gravity in sapwood, opposite trend was observed in heartwood. There were difference in shrinkage based on origin of apricot, and higher growth rate wood had higher shrinkage and T/R ratio. Compression Young's modulus, bending strength, bending Young's modulus, and compact strength was difference among different origin of apricot. Higher growth rate wood had higher tensile strength, and also there was difference amont different origin of apricot. In hardness, 3 different directions had all difference among different origin of apricot, and higher growth rate wood showed higher hardness than others. Based on overall physical and/or mechanical properties and growth rate, apricot from Bancroft was best quality in current.

• Journal of Korean Society of Forest Science
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• v.111 no.3
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• pp.357-364
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• 2022

We investigated the early growth characteristics of Quercus rubra planted in six regions (Hwaseong, Yangpyeong, Pyeongchang, Samcheok, Chungju, and Gimje) in South Korea in relation to soil physicochemical properties and meteorological factors. Q. rubra (1-0) were planted at a density of 3,000 trees ha^-1. The average height, root collar diameter (RCD), and volume of 8-year-old Q. rubra planted in 2014 were 3.52 m, 3.84 cm, and 0.0023 m³, respectively. The growth parameters of Q. rubra were the highest and lowest in Hwaseong and Pyeongchang, respectively. Correlation analysis among the soil physicochemical properties, meteorological factors, and plantation growth characteristics found that pH was the only soil factor negatively correlated with RCD, and the other soil factors were not significantly correlated with the growth characteristics. However, growth characteristics were positively correlated to average temperature from March to October and daily maximum temperature; and they were negatively correlated to altitude, topology, and the number of rainy days from March to October. In particular, the trees planted in Hwaseong area showed the best early growth characteristics because this area had the highest daily maximum temperature, the x average temperature from March to October, the low altitude, and it is located close to the foot of a mountain. In Pyeongchang, the early growth characteristics were negatively affected by winter cold damage because of the high altitude, low daily minimum temperature, and damage by wild animals. In Hwaseong, meteorological factors such as temperature and altitude were more highly correlated to growth characteristics of Q. rubra than the physicochemical soil properties. These results will provide useful information for determining suitable sites for Q. rubra plantations and for predicting early growth characteristics in response to environmental factors.

• Journal of Forest and Environmental Science
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• v.34 no.4
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• pp.338-351
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• 2018

This study was conducted in a long-term experimental forest in the central hardwoods region of southwestern Michigan to retrospectively examine the role of past forest management practices and climate on red oak (Quercus rubra L.) productivity. Initially, in 1971, plots within the experimental forest were treated separately with a clearcut and shelterwood regeneration harvest in an attempt to increase red oak regeneration. From 1987-1989, a new study was initiated within a portion of the clearcut and shelterwood plots to evaluate the effectiveness of additional oak crop tree release using mechanical and chemical applications. Cumulative diameter and mortality rates of 719 red oaks were monitored across the four silvicultural treatments: Clearcut-A (clearcut without additional release treatment), Clearcut-B (clearcut with additional release treatment), Shelterwood-A (shelterwood without additional release), and Shelterwood-B (shelterwood with additional release) plus an untreated control. Increment cores were obtained from red oak trees and neighboring competitor species. Tree-ring analyses (dendrochronology) were applied to examine the effect of these silvicultural treatments and climatic factors (temperature and precipitation) on red oak productivity. The results indicated that crop tree release following a clearcut or shelterwood harvest reduced mortality rates and thus increased survival of red oak. Red oak in control plots or plots only receiving the initial regeneration harvesting treatment and no additional competition release were negatively affected by climatic stress, which included summer moisture stress. In contrast, red oak in plots that received the competition release treatment from shade tolerant tree species not only had higher tree level productivity (i.e., tree basal area) and lower mortality rates, but were also relatively more resilient to climatic stress by showing limited or no associations between climate and growth.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.3
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• pp.165-173
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• 2007

In the previous study, we reported the antioxidative and cellular protective effects of Jeju native plant extracts. In this study, we investigated the anti-oxidative, anti-wrinkle and whitening effects of new 37 plant extracts collected from self-growing plants in Jeju island. Their anti-oxidant activities were measured by the 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging assay and reactive oxygen species(ROS) scavenging assay in $Fe^{3+}-EDTA/H_2O_2$ system. The cytoprotective properties of 37 plant extracts were assessed in the rose-bengal sensitized photohemolysis of human erythrocytes. The inhibitory effect of 37 plant extracts on tyrosinase were investigated to assess their whitening efficacy. Finally, their anti-elastase activities were measured to predict the anti-wrinkle efficacy in the human skin. The results showed that the extracts of Myrica rubra stem bark and Securinega suffruticosa have the free radical scavenging activity($FSC_{50}:\;5,\;8{\mu}g/mL$, respectively), and the extracts of Quercus acutissima leaf and Securinega suffruticosa stem bark have the prominent ROS scavenging activity($OSC_{50}:\;0.009{\mu}g/mL$). Photohemolysis of erythrocytes in the presence of rose-bengal as a sensitizer was inhibited by the extracts of Securinega suffruticosa stem bark and Salix koreensis stem(${\tau}_{50}$, 895 min, 640 min at 50 ${\mu}g/mL$, respectively. Myrica rubra stem bark extract(77.8% at 200 ${\mu}g/mL$) and Salix koreensis stem extract(76.2% at 200 ${\mu}g/mL$) also have the inhibitory effect on tyrosinase and elastase activities, respectively. These results indicated that the stem park of Myrica rubra, Securinega suffruticosa, and Camellia japonica, the stem of Salix koreensis, and the leaf of Quercus aqutissima and Camellia japonica could have e benefitial effects when they are added as ingredients in cosmetics.

• Journal of the Korean Wood Science and Technology
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• v.24 no.3
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• pp.37-44
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• 1996

포수상태(包水狀態)의 루부라참나무(Quercus rubra) 시험편을 3가지 등온조건(等溫條件)에서 건조한 결과를 비정상상태(非正常狀態)의 확산(擴散)모델로 추정한 결과와 비교하였다. 표면이 충분히 젖은 상태인 건조초기에는 불안정(不安定)한 확산현상(擴散現象)이 관찰되었으나, 함수율(含水率)별 건조속도의 변이를 Fick's의 확산법칙과 비교할 때 유사한 형태를 보였다. 실험에서 얻은 건조조건별 건조곡선은 확산모델의 수치해석(數値解析) 결과와 거의 일치하였으며, 같은 평위함수율(平衛含水率) 조건에서 건조온도의 증가는 목재표면 보다 내부의 함수율 변화에 더 크게 영향하여 결과적으로 낮은 온도에서의 건조조건이 목재 내의 수분경사(水分傾斜)를 급하게 하는 것으로 밝혀졌다. 본 연구를 통해 목재 건조 중의 내부에 발생하는 수분경사를 추정하는데 비정상상태의 확산모델이 모든 함수율 범위에 걸쳐 유용하게 사용될 수 있음이 밝혀졌다.