• Applied Chemistry for Engineering
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• v.21 no.4
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• pp.469-474
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• 2010

Wood has an essential drawback such as high combustion ability. The purpose of this paper is to examine the combustion properties of the quercus variabilis and zelkova serrata dried at room temperature. The cone calorimeter (ISO 5660-1) was used to determine the heat release rate (HRR) and fire smoke index, as well as CO/$CO_2$ production and smoke obscuration. The total heat release (THR), $140.2\;MJ/m^2$ of the quercus variabilis under an external $50\;kW/m^2$ was high in comparison with THR $85.7\;MJ/m^2$ for the zelkova serrata. Furthermore, the quercus variabilis has high total smoke production (TSP), $3.50\;m^2$ compared with TSP $0.65\;m^2$ of zelkova serrata. Thease results depend on the bulk density of tested wood species. In addition, the CO/$CO_2$ production ratio of zelkova serrata and quercus variabilis was measured as 0.053, 0.043, respectively. Also, zelkova serrata showed an increase of fire-resistance attributed to char formation compared with that of quercus variabilis.

• Fire Science and Engineering
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• v.21 no.3
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• pp.41-46
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• 2007

The combustion characteristics of surface forest fire fuels was analysed using variable external irradiation level. The characteristics such as ignition time, ignition temperature, critical heat flux and mass loss rate were measured. Fuel samples were exposed to incident heat fluxes from 8 to $50\;kW/m^2$. For the measurement of various combustion characteristics, the size of specimen holder was $100\;mm{\times}100\;mm{\times}12\;mm$ and the fuel samples grinded by electric mill were the fallen leaves of Quercus variabilis and Pinus densiflora. As results, the occurrence of ignition is possible to the heat flux more than $9\;kW/m^2$. The fuel of Pinus densiflora keeps its high temperature longer than that of Quercus variabilis during the combustion process. The results of measurement shows that the maximun and average mass loss rate of Quercus variabilis larger than that of Pinus densiflora.

• Journal of agriculture & life science
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• v.45 no.4
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• pp.65-72
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• 2011

The objective of this research is to develop biomass allometric equation for Pinus densiflora in central region and Quercus variabilis. To develop the biomass allometric equation by species and tree component, data for Pinus densiflora in central region is collected to 30 plots (70 trees) and for Quercus variabilis is collected to 15 plots (32 trees). This study is used two independent values; (1) one based on diameter beast height, (2) the other, diameter beast height and height. And the equation forms were divided into exponential, logarithmic, and quadratic functions. The validation of biomass allometric equations were fitness index, standard error of estimate, and bias. From these methods, the most appropriate equations in estimating total tree biomass for each species are as follows: $W=aD^b$, $W=aD^bH^c$; fitness index were 0.937, 0.943 for Pinus densiflora in central region stands, and $W=a+bD+cD^2$, $W=aD^bH^c$; fitness index were 0.865, 0.874 for Quercus variabilis stands. in addition, the best performance of biomass allometric equation for Pinus densiflora in central region is $W=aD^b$, and Quercus variabilis is $W=a+bD+cD^2$. The results of this study could be useful to overcome the disadvantage of existing the biomass allometric equation and calculate reliable carbon stocks for Pinus densiflora in central region and Quercus variabilis in Korea.

• Korean Journal of Environmental Biology
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• v.27 no.2
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• pp.191-197
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• 2009

In order to characterize the ecological traits of Q. mongolica, we treated the seedlings of this species with three environmental factors, light, moisture and nutrient gradients from March to October 2007, and measured morphological and ecological 17 characters. Lastly calculated ecological niche breadth and niche overlap between Q. mongolica-Q. acutissima and Q. mongolica-Q. variabilis, and analysed them with a special reference to ecological distribution pattern and their competition relationship in Korea. The ecological niche breadth of Q. mongolica showed the lowest in nutrient treatment, but the highest in soil moisture treatment. The ecological niche value under light was intermediate. On comparison of the ecological niche breadth of three oak species, Q. mongolica showed the highest in light environment, which might be a reason for the dominant distribution in the forest plant community, Korea. The ecological niche overlap of Q. mongolica-Q. acutissima and Q. mongolica-Q. varabilis was the widest in moisture treatment, but the narrowest in nutrient treatment and the intermediate in light one. These results means that these three oak species be most competitive in moisture environment than light or nutrient one, and that there are least differentiated among oak species for soil moisture condition. Cluster and PCA ordination showed that Q. mongolica and Q. acutissima were more closely arranged than Q. mongolica and Q. variabilis. From these results, it can be explained that Q. mongolica have more similar ecological niche with Q. acutissima than with Q. variabilis, consequently competition between Q. mongolica and Q. acutissima is intensive than Q. mongolica and Q. variabilis for environment condition, especially in soil moisture.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.83-83
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• 2018

최근 매실나무를 기주로 한 겨우살이의 인공재배에 성공함에 따라, 식 의약품과 화장품의 소재 및 산업화 가능성을 확인하기 위해 80% 에탄올 및 증류수 초음파추출물의 총 폴리페놀 플라보노이드 함량 및 DPPH free radical 소거능을 측정하였다. 경기도 남양주시에서 인공재배한 매실나무겨우살이(동결건조) 및 강원도 홍천에서 채취한 자연산 굴참나무겨우살이(열풍건조, $30^{\circ}C$, 7day)의 80% 에탄올, 증류수 초음파추출물에 대한 총 폴리페놀 및 플라보노이드함량 그리고 DPPH free radical 소거능을 측정한 결과, 시료의 농도에 비례하여 총 폴리페놀과 플라보노이드 함량 그리고 DPPH free radical 소거능이 증가하였다. 총 폴리페놀 함량은 매실나무겨우살이의 80% 에탄올 추출물이 5,000ppm에서 $192.63{\mu}g/ml$로 가장 많았으며, 굴참나무겨우살이의 물 추출물이 100ppm에서 $4.86{\mu}g/ml$로 가장 낮고 매실나무겨우살이가 모든 용매에서 더 많은 폴리페놀을 함유한 것으로 확인되었다. 총 플라보노이드 함량은 굴참나무겨우살이의 80% 에탄올 추출물이 5,000ppm에서 $83.59{\mu}g/ml$로 가장 높았으며, 매실나무겨우살이 물 추출물이 $4.6{\mu}g/ml$로 가장 낮았고 굴참나무겨우살이가 모든 용매에서 더 많은 플라보노이드를 함유한 것으로 확인되었다. DPPH free radical 소거능은 80% 에탄올 추출물 5,000ppm에서 매실나무겨우살이 81.75%로 시료 중 가장 높았고, 굴참나무겨우살이 물 추출물 100ppm이 3.55%로 가장 낮음을 확인할 수 있었다. 본 연구 결과에 따르면, 겨우살이를 초음파추출법으로 추출할 때, 80% 에탄올 초음파추출물이 더 많은 폴리페놀을 함유하여 80% 에탄올 추출물이 물 추출물보다 비교적 적합하였다. 80% 에탄올로 초음파추출 하였을 때 동결건조 한 매실나무겨우살이가 열풍건조한 자연산 굴참나무겨우살이보다 더 많은 폴리페놀을 함유하고 있고, 더 높은 DPPH free radical 소거능을 보여줌에 따라 식 의약품 그리고 화장품의 소재화 및 산업화의 가능성이 높음을 확인할 수 있었다.

• Journal of Korean Society of Forest Science
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• v.78 no.2
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• pp.151-159
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• 1989

The present study has been designed to define the effects of photosynthetically active radiation, leaf temperature, and water stress on photosynthesis and respiration of leaves of four oak species (Quercus mongolica, Quercus aliens, Quercus variabilis, and Quercus serrate). The results obtained are as follows : 1. The estimated light compensation points at which Pn approached zero were 38, 24, 20, and $18{\mu}Em^{-2}s^{-1}$ for Q. aliens, Q. variabilis, Q, mongolica, and Q. serrate, respectively. The light saturation points occurred at $500{\mu}Em^{-2}s^{-1}$ in three oak species except Q, aliens. 2. The maximum rates of Pn were 19.7, 15.2, 11.2, and 11.0 mg $CO_2$ $dm^{-2}h^{-1}$ for Q. variabilis, Q. serrate, Q. monglica, and Q. aliens leaves, respectively. 3. The transpiration rates of Q. variabilis and Q. serrate leaves were slightly higher than those of Q. mongolica and Q. aliens leaves at various photosynthetically active radiations(PAR), but cuticular transpiration rates at dark were similar in four oak species. 4. The optimum photosynthesis occurred at $25^{\circ}C$ in Q. aliens, Q. variabilis, and Q. serrate leaves, but $20^{\circ}C$ in Q. mongolica leaves. In four oak species, the net photosynthesis approached zero at about $40^{\circ}C$. 5. The dark respiration rates of leaves exhibited the following ranking of species : Q, variabilis > Q. mongolica > Q. aliens > Q. serrate. 6. The maximum productive efficiency (Pg/Rd) of leaves occurred highest in Q, serrate at $20^{\circ}C$, then in Q. mongolica at $20^{\circ}C$, then in Q, aliens at $25^{\circ}C$, and finally in Q. variabilis at $15^{\circ}C$. 7. The decrease of net photosynthesis in Q. serrate began at about -1.2 MPa, and then approached zero at -2.9 MPa of leaf water potential. The decrease of net photosynthesis began at 3% of water loss, and then approached zero at 17.5% of water loss. 8. As indicated by tissue-water relations parameters, it may be suggested that Q. aliens and Q. variabilis are more tolerant and favored on xeric forest soils than Q. mongolica and Q. serrate.

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.274-279
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• 2011

In order to know the effect of seed size on the early plant life history, we measured the rate of germination, early growth and winter survival of four oak species with different acorn size (large, medium and small). The mean germination rate was higher in the larger seed species ($Q.$ $acutissima$ and ($Q.$ $variabilis$) than those of the smaller seed species ($Q.$ $aliena$ and $Q.$ $serrata$). Within $Q.$ $variabilis$, the germination rate decreased with larger acorn size class but that of rest other species was not significantly affected by the acorn size. The early mean growth rate decreased with acorn size in the order of $Q.$ $acutissima$, $Q.$ $variabilis$, $Q.$ $aliena$ and $Q.$ $serrata$. The early mean growth rate was higher in large or medium size than in small size of $Q.$ $acutissima$ and $Q.$ $variabilis$, but it showed no difference with acorn size in $Q.$ $aliena$ and $Q.$ $serrata$. Survival rate in winter was the highest in the medium acorn size among 4 oak species, the seedling of $Q.$ $serrata$ and $Q.$ $variabilis$ did not survive in both large and small acorn size. These results indicate that seed size influences a different effect on the early plant life history stage.

• Korean Journal of Environment and Ecology
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• v.13 no.4
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• pp.354-366
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• 2000

지리산국립공원 대원계곡의 삼림군집구조를 분석하여 국립공원관리의 기초자료를 제공하기 위하여 기조사지역(이경재 등, 1991)이외의 지역에 대해 39개 조사지(100m2)를 설정하고 식생조사를 실시하였다 Classification의 한 기법인 TWINSPAN을 사용하여 군집을 분리하였으며 그 결과 느릅나무-굴참나무군집(군집 I) 졸참나무-굴참나무군집(군집II) 졸참나무군집(군집III-V) 신갈나무군집(군집VI) 그리고 서어나무-노각나무군집(군집VII)의 7개 군집으로 나뉘었다 각 군집에 대해 우점도 종다양도 유사도 종수 및 개체수 그리고 흉고직경 등의 분석을 통해 군집의 종조서을 살펴본 결과 지리산 대원계곡의 삼림은 졸참나무 굴참나무 신갈나무 등의 참나무가 주류를 이루고 있었으며 점차 서어나무와 노각나무등으로 천이가 진행되어갈 것으로 판단되었다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.3
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• pp.120-126
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• 2016

This study was carried out to examine the relationships between seasonal variations of soil $CO_2$ efflux rates and soil environmental factors in matured Pinus densiflora and Quercus variabilis stands in the Wola national experimental forests, southern Korea. Soil $CO_2$ efflux rates were measured monthly from March 2015 to February 2016. Mean soil $CO_2$ efflux rates during the study period were significantly higher in the Q. variabilis ($mean{\pm}standard$ error; $2.27{\pm}0.22{\mu}mol\;m^{-2}s^{-1}$) than in the P. densiflora ($1.63{\pm}0.12{\mu}mol\;m^{-2}s^{-1}$) stands. Mean soil water content and pH were also significantly higher in the Q. variabilis ($26.96{\pm}0.93%$, pH 5.19) than in the P. densiflora ($21.32{\pm}0.89%$, pH 4.87) stands, while soil temperature was not significantly different between the P. densiflora ($13.92{\pm}0.67^{\circ}C$) and in the Q. variabilis ($13.52{\pm}0.70^{\circ}C$) stands. $Q_{10}$ values were higher in the Q. variabilis (3.35) than in the P. densiflora (2.72) stands. The results indicate that soil $CO_2$ efflux rates in Q. variabilis stand could be more sensitive by the change of soil temperature compared with P. densiflora stand under a similar site environmental condition.

• Korean Journal of Environment and Ecology
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• v.14 no.4
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• pp.296-302
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• 2001

계룡산국립공원 연천봉고개(해발 700m)를 중심으로 남향사면인 시원사~원천봉고개와 북향사면인 갑사~연천봉고개를 대상으로 사면방향과 해발고에 따른 교목층과 아교목층의 산림구조를 조사분석하였다. 남향사면은 북향사면에 비하여 교목측의 밀도는 높은 반면 평균흉고직경은 작았다. 특수한 지형인 주능선부에 위치하는 정부를 제외하며, 해발고가 높아짐에 따라 교목층과 아교목층 전체의 평균흉고직경과 흉고단면적인 남향사면에서는 감소하는 경향을 보였다. 북향사면은 남향사면에 비하여 교목층과 아교목층 전체의 동다양도와 균재고가 높았다. 남향사면에서 해발고가 높아짐에 따라 중요치가 증가하는 수종은 느티나무, 졸참나무, 까지박달, 신갈나무등이었으며, 중요치가 감소하는 수종은 굴참나무, 서어나무, 때죽나무 등이었다. 북향사면의 경우 해발고가 높아짐에 따라 중요치가 증가하는 수종은 까치박달, 쪽동백나무 등이며, 중요치가 감소하는 수종은 때죽나무, 졸참나무 등이었다. Cluster 분석결과 남향사면중, 하부의 굴참나무-낙엽활엽수군집지, 남향사면 상부와 북향사면상, 중의 신갈나무-낙엽활엽수군집, 북향사면 하부와 정부의 신갈나무-소나무군집 등 3개 군집으로 구분되었다. 굴참나무, 산벚나무, 밤나무 등 3개 수종간에는 유의적인 정의 상관이 있었으며, 유의적인 정의 상관을 보인 굴참나무, 산벚나무, 밤나무 등 3개 수종은 당당풍과 유의적인 부의 상관이 있었다.