• 한국안전학회지
• /
• 제26권4호
• /
• pp.111-119
• /
• 2011

This study was designed to provide basic data applicable to fire investigation through consideration of combustion products and propose vulnerability of combustibles through analysis of $CO_2$ emission. In order to achieve these research objectives, characteristics of combustion products such as smoke release rate of each part(raw leaves, branches and barks), $CO_2$ emission and ash production were considered targeting on 6 oak species(Quercus variabilis Blume, Quercus aliena Blume, Quercus serrata, Quercus mongolica Fisch, Quercus dentata Sapling and Quercus acutissima) using cone calorimeter and smoke density tester. As a result, it was found that raw leaves release smoke more relatively than branches and barks, when they burn, and that Quercus variabilis Blume has the highest smoke density. Also, Quercus acutissima released CO and $CO_2$ which are respectively, 6.67 times and 1.43 times more than Quercus variabilis Blume with low $CO_2$ emission. In addition, branches released CO and $CO_2$ more relatively. There was a big difference in ash production among raw leaves(3.1 g), branches(10.5 g) and barks(16.43 g). It was identified that Quercus serrata produces ashes which are nearly 9.95 times more than Quercus variabilis Blume. It demonstrates that Quercus serrata contains relatively higher minerals and that Quercus variabilis Blume can leave lots of traces like stain and carbonization, as it releases smoke a lot and it's difficult to predict visibility, when a forest fire breaks out in its community area. It is also considered that smoke particles containing oil in the air leave strain on the surface of a tree, and that CO and $CO_2$ emission increases, when crown fire to burn branches breaks out.

• Journal of the Korean Wood Science and Technology
• /
• 제21권1호
• /
• pp.15-20
• /
• 1993

X-ray diffractograms of the vessel elements and the wood fibers of Quercus variabilis BLUME were recorded and resolved into characteristic reflections of cellulose I. Some differences were observed in the ratio of integrated intensity and crystallinity index between vessel elements and wood fibers. Present results suggest that cellulose crystal structure in the hardwood species was varied with the elements of wood.

• Journal of the Korean Wood Science and Technology
• /
• 제16권2호
• /
• pp.90-97
• /
• 1988

The rate of utilization of the oak cork (bark of Quercus variabilis Blume) ranges only 40-50%. Therefore, this study was carried out to investigate the chemical properties of the oak cork for increasing the utility. 1) The contents of alkali extractives, organic solvent extractives and ash in the oak cork are similar to those of other barks, but hot and cold water extractives and lignin contents are lower than those of the wood. The carbohydrate (cellulose and hemicellulose) content of the oak cork is similar to that of other barks. The suberin contents in the first and the second bark of the oak cork are 34.8 and 32.2% respectively, in the dry weight. 2) Inorganic component contents of the first bark are similar to those of the second. The pH of the first and the second bark are 3.9 and 4.2%. The caloric values of the first and second bark are 6,263 Kcal/kg, and 5,828 Kcal/kg, respectively, and these caloric values are higher than those of other barks. The sclerencymatous cell content of the first bark which is related to the quality of the oak cork is lower than that of second bark, the contents of the sclerenchymatous cell and lignin show the positive correlation. 3) In the dimension of the cross sectioned cork cell, the first bark is bigger than that of the second. The shape of the cork cell is globular shape in the early bark and discoid shape in the late bark. The cross and the radial section are the same shape, but the tangential section shows difference from the other section.

• 한국안전학회지
• /
• 제26권5호
• /
• pp.118-129
• /
• 2011

In this study, species resistant to forest fire were extracted from high trees through an investigation of combustion mechanism. Here, the average flameless ignition temperatures of living leaves, branches and barks of oak were respectively, $365^{\circ}C$, $440^{\circ}C$ and $435^{\circ}C$, and the average flameless ignition temperatures of living leaves, branches, barks and cones of pine tree were respectively, $320^{\circ}C$, $405^{\circ}C$, $435^{\circ}C$ and $363^{\circ}C$. It shows that generally, pine tree has a lower flameless ignition temperature than oak and thus, has a relatively high risk of flameless ignition. When comparing risk of fire depending on ignition characteristics, Quercus serrata had a low risk of stem fire, and Quercus acutissima and Quercus serrata had a low risk of crown fire, as well. When analysing risk of fire depending on a duration of flame, also, Quercus dentata had a low risk of stem fire, and Quercus variabilis Blume had a low risk of crown fire too. Lastly, when comparing risk of fire, according to heat release rates, Quercus acutissima had a low risk of stem fire, and Quercus acutissima and Quercus dentata had a low risk of crown fire, as well. In conclusion, it was observed that as fire-resistant species, Quercus serrata and Quercus dentata have a low risk of ignition, Quercus variabilis Blume has a short duration of flame after discharging ignition when a forest fire occurs, and Quercus acutissima, Pinus Rigida and Antipathes japonica Brook have low heat release rates.

• 한국산림과학회지
• /
• 제108권2호
• /
• pp.139-146
• /
• 2019

This study was conducted to determine the carbon (C) and nitrogen (N) distribution within tree components (i.e., stem, branches, leaves, and roots) of the Japanese larch (Larix kaempferi Carriere) plantation and natural oriental cork oak (Quercus variabilis Blume) stands. Fifteen Japanese larch and 15 oriental cork oak trees were destructively sampled to compare the C and N stocks in the components of the trees from three different regions-Hadong-gun, Hamyang-gun and Sancheong-gun-in Gyeongnam Province, South Korea. Species-specific allometric equations were developed to estimate the C and N contents in the tree components based on the diameter at breast height (DBH). There were differences in mean C and N concentrations between the Japanese larch and the oriental cork oak. The mean C concentrations of the tree componentswere significantly higher in Japanese larch than in oriental cork oak; whereas, the N concentration in the stems was significantly lower in Japanese larch than in oriental cork oak. The allometric equations developed for C and N content were significant (p < 0.05) with a coefficient of determination ($R^2$) of 0.76 to 0.99. The C and N stocks in the tree components do not appear to be affected by the species such as Japanese larch plantations and oriental cork oak stands. This study emphasizes the importance of C and N concentrations to estimate the C and N distribution according to tree components in different tree species.

• 한국자원식물학회지
• /
• 제20권6호
• /
• pp.540-543
• /
• 2007

We have investigated the vegetation in the peninsula located in Ongjeong-Li Seomyeon in Youngweol-gun. Since this is a limestone area, boxtrees, Abelia mosanensis T. H. Chung ex Nakai, and Selaginella stauntoniana Spring were abundant, as these are types of vegetation characteristic of limestone areas. Pinus densiflora S. et Z. was the most dominant woody plant, but vegetational changes, such as the dominance of Quercus variabilis Blume, Quercus dentata Thunb, and Quercus mongolica Fischer, were observed in spots. In particular, the growth of nursery plants of pinus densiflora S. et Z. was not observed, and young trees like Quercus mongolica Fischer grow as low vegetation of Pinus densiflora S. et Z.. Thus, the ecological succession of Quercus mongolica Fischer is predicted. Outside the investigation area, as herbaceous plants, various vegetations were observed, including Selaginella stauntoniana Spring, Thalictrum coreanum H. Lev., Mukdenia rossii(Oliv.) Koidz., Platanthera freynii Kraenzl., Cephalanthera longibracteata Blume, Potentilla dickinsii Franch., Patrinia rupestris(Pall.) Juss., Swertia pseudochinensis H. Hara, Vicia venosa(Willd.) Maxim., Pyrola japonica Klenze ex Alef., Disporum smilacinum A. Gray, Artemisia stolonifera(Maxim.) Kom. for. Stolonifera, Smilax nipponica Miq., Adenophora triphylla var. japonica(Regel) H. Hara, Isodon inflexus(Thunb.) Kudo, Gentiana scabra Bunge for. Scabra, Polygonatum odoratum var. pluriflorum(Miq.) Ohwi, Dioscorea quinqueloba Thunb., Syneilesis palmata(Thunb.) Maxim., Asparagus schoberioides Kunth, Eupatorium japonicum Thunb. ex Murray, Galium kinuta Nakai & Hara, Saxifraga fortunei var. incisolobata, Lilium amabile Palib., Siberian iris, Dictamnus dasycarpus Turcz., Atractylodes ovata(Thunb.) DC., and Lysimachia clethroides Duby.

• Journal of the Korean Wood Science and Technology
• /
• 제21권4호
• /
• pp.45-54
• /
• 1993

This study examines the differences in structures, physical and mechanical properties between domestic(Quercus variabilis Blume) and foreign(Quercus suber L.) corks. The results obtained are as follows: 1. The cork tissue consists of cork cells, lenticels, sclereids and dark-brown zone. There was a significant difference in ratio of cork cells between foreign cork(93 %) and domestic cork(87 %). The ring width and width of late cork of the foreign cork were wider than those of domestic cork. But the percentage of late cork of domestic cork was richer than that of foreign cork. The size of cork cell of foreign cork was larger by about two times than that of domestic cork. 2. The density was slightly higher in domestic cork(0.22 g/$cm^3$) than in foreign cork(0.19 g/$cm^3$). During first 24 hours, the amount of water absorption of the foreign cork was greater than that of domestic cork. However, after 24 hours, the tendency was reversed. The level of EMC was higher in domestic cork than in foreign cork. Total shrinkage in the radial and tangential directions was larger in domestic cork than tn foreign cork. In the longitudinal direction, the tendency was reversed. There was no difference in total swelling in three woody directions between the two corks. 3. The modulus of elasticity in compression in the logitudinal and tangential direction was higher in domestic cork than in foreign cork, but the tendency was reversed in the radial direction. Both corks showed 95% of recovery rate after 24 hours when they were compressed by 0.5. There were no differences in tension strength and Brinell,s hardness bet ween domestic and foreign corks.

• Journal of Forest and Environmental Science
• /
• 제38권1호
• /
• pp.48-54
• /
• 2022

This study was conducted to examine litter inputs and litter decomposition rates following thinning, which is among the most important forest management activities that enhance the beneficial functions in Korean forests. Litter inputs and litter decomposition rates following a 2-year elapse from thinning in Pinus densiflora and following a 7-year elapse from thinning in Quercus variabilis stands were measured for 2 years from 16 sites in three regions (Sancheong-gun, Uiryeong-gun, and Jinju-si) in Gyeongsangnam-do, Korea. Annual needle litter inputs in P. densiflora stands were significantly decreased following thinning, whereas annual broadleaved leaf litter inputs in Q. variabilis stands were not significantly different between thinned and unthinned treatments. The annual mean total litter inputs in both tree species were significantly lower in the thinned (P. densiflora: 3,653 kg ha^-1 year^-1; Q. variabilis: 4,963 kg ha^-1 year^-1) compared to the unthinned stands (P. densiflora: 5,138 kg ha^-1 year^-1; Q. variabilis: 5,997 kg ha^-1 year^-1) during the study period. The mass loss rates from decomposing needle litter in P. densiflora stands were significantly lower (p<0.05) in the thinned stands than in the unthinned stands for two sampling dates of the eight included in the study, whereas the decomposition rates from decomposing leaf litter in Q. variabilis stands were not affected by thinning. The results indicate that thinning effects on total litter inputs remained clear following a 2-year elapse from thinning in P. densiflora stands and following a 7-year elapse from thinning in Q. variabilis stands.

• 생명과학회지
• /
• 제14권6호
• /
• pp.951-962
• /
• 2004

병원성세균에 대한 자생식물 열수 추출물 141종의 항균효능을 검색하였다. 실험대상 식물은 생체 채집하여 건조 후 열수 추출하여 시료화 하였으며 디스크 확산법으로 항균력을 측정하였고 시험 대상 균주로는 그람양성균 7주 및 그람음성균 12주를 사용하였다. 그 결과 그람양성군 1주 이상에 항균효능을 보이는 식물은 55종이었으며 특히 달맞이꽃(꽃), 석류(과피), 굴참나무(도토리), 사방소리 나무(미성숙과), 물오리나무(미성숙과), 칡(꽃), 이질풀(지상부), 배롱나무(꽃)은 6주 이상에서 광범위 항균 스펙트럼를 보였다. 그람음성균 1주 이상에 항균효능을 보이는 식물은 45종이었으며 달맞이 꽃(꽃), 석류(과피), 굴참나무(도토리), 오미자(성숙과), 사방오리나무(미성숙과), 물오리나무(미성숙과), 목련(미성숙과)은 8주 이상에서 광범위 항균스펙트럼을 보였다. 본 연구결과 식용 가능하며 항균효능을 보인 달맞이꽃 (꽃), 석류(과피, 꽃), 굴참나무(도토리), 오미자(성숙과)의 열수 조추출물은 식품 보존제 및 가축 식이사료 등에 첨가하여 병원균 감염예방 등의 항균효과를 기대할 수 있을 것으로 사료된다.

• 한국산림과학회지
• /
• 제102권1호
• /
• pp.156-160
• /
• 2013

전 지구적 온난화는 광합성과 생장을 포함한 육상생태계의 생산성에 영향을 미칠 것으로 예상되고 있다. 실외 실험적 온난화가 굴참나무(Quercus variabilis Blume) 3년생 묘목의 엽록소 함량 및 순광합성률에 미치는 영향을 알아보고자 1년생 묘목을 2010년 4월에 식재하고 2010년 11월부터 적외선등을 이용하여 온난화 처리구의 기온을 대조구보다 $3^{\circ}C$ 증가시켰다. 2012년 5월부터 10월까지 굴참나무 묘목의 총 엽록소 함량과 순광합성률을 측정한 결과 총 엽록소 함량은 5월, 7월, 8월, 9월, 10월에 온난화 처리구에서 대조구보다 높았으나, 이들 간의 차이는 10월에만 통계적으로 유의하였다. 또한 순광합성률은 5월, 9월, 10월에 온난화 처리구에서 대조구보다 각각 57.0%, 21.4%, 89.6% 높았으나, 5월과 10월에 이들 간의 차이가 통계적으로 유의하게 나타났다. 온난화 처리에 따른 굴참나무 묘목의 봄과 가을철 엽록소 함량 및 순광합성률 증가 경향은 생장을 일찍 시작하고 늦게까지 지속함으로써 생장기간이 늘어나는 것과 관련이 있을 것으로 추정된다.