• 한국화재소방학회논문지
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• 제23권3호
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• pp.73-78
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• 2009

Fire whirl은 도시 및 산림화재와 같이 광범위한 지형에서 주로 발생하며, 화염주위 환경의 불안전성에 의해 발생하는 현상이다. Fire whirl은 드물게 발생하지만, 높은 흡입력과 양력을 가지게 되어 연소속도를 증가시키는 매우 위험한 현상이다. 본 연구에서는 산림화재에서 발생하는 fire whirl 특성에 대한 고찰을 위해 굴참나무 낙엽을 이용한 fire whirl 실험 및 수치해석 연구를 실시하였다. 실험 결과 유입공기의 속도가 증가함에 따라 화원주위의 회전강도가 증가하여 발열량 및 화염길이가 일반 풀화재에 비해 최대 22.8%, 18.4% 증가하였으며, 수치해석은 실험결과와 유사한 경향을 나타내었다.

• Journal of Plant Biology
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• 제15권3호
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• pp.1-8
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• 1972

A comparison between the productivity of the evergreen needle pine(Pinus densiflora) and of the deciduous broad leaved oak(Quercus mongolica) stands, which is located near Choon-Chun city, Kangwon dist. have been established. The pine stand had a stand density of 938 trees per ha and oak stand had of 638 trees per ha. The diameter at breast height (D) and the height of tree (H) of each tree were measured in sample plot of 800$m^2$. Twelve standard sample trees chose from the sample area felled down, and then weighed the stem, branches and leaves separately, according to both the stratified clip technique and the stem analysis. The vertical distribution of photosynthetic system was arranged effectively for high productivity in the productive structure of both trees. The allometric relation between D2H and dry weight of stem (Ws), branches (Wb) and leaves (Wl) of pine were approximated by log Ws=0.6212 log D2H-0.5383 log Wb=0.4681 log D2H-0.7236 log Wl=0.2582 log D2H-5.1567 and those of oak were approximated by log Ws=0.5125 log D2H＋0.0231 log Wb=0.5125 log D2H-0.3755 log Wl=0.8721 log D2H-2.9710 From the above, the standing crops of pine and oak in the sample area were estimated to be as much as 38.83ton and 48.11 ton of dry matter, above ground, per ha, respectively. Annual net production as the sum of the biomass newly formed during one year was appraised at 12.66ton/ha.yr in pine stand and at 8.74 ton/ha.yr in oak. The reason of high productivity of pine stand compared with oak might be resulted from much more about 4 times of the amount of the photosynthetic system, but less non-photosynthetic one of pine than those of oak. To increase the productivity of the forest stands investigated it was necessary to make densly a stand density, to be abundant in the inorganic nutrients and to preserve much water in soil to conserve the litters.

• Journal of Plant Biology
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• 제20권3호
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• pp.109-118
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• 1977

Seasonal distribution of N, P and K contents and their cycling were studied in Korean oak (Quercus acutissima) and Korean alder (Alnus sibirica) stands in central part of Korean peninsula. The amounts of three minerals were high in young leaves but gradually decreased with the process of leaf development in both stands. The amounts of minerals in the branches, trunks and roots were decreased in summer, however, they increased again in autumn. Seansonal changes of these minerals were not significant in the two stands. The amounts of phosphorus and potassium in plant and soil were higher in the oak stand than the alder one, but those of nitrogen were reversed. The amounts of minerals absorbed during one year were greater in the oak stand than in the alder one, but those returned into soil through mineralization of litter were less in the former than in the latter. The nutrient requirements of the oak stand were greater than the alders, but the cycling rate, the ratio of the amount of minerals absorbed to returned, was opposite.

• 한국산림과학회지
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• 제78권2호
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• pp.151-159
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• 1989

우리나라 온대림(溫帶林)에 분포(分布)하는 낙엽성(落葉性) 참나무류(類)의 생리(生理) 생태적(生態的) 습성(習性)을 밝히기 위하여 이번 연구에서는 신갈나무, 갈참나무, 굴참나무, 졸참나무 엽(葉)의 광합성속도(光合成速度)와 호흡속도(呼吸速度)에 미치는 광(光), 온도(溫度), 수분(水分)의 영향을 조사(調査) 하였다. 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 졸참나무, 신갈나무, 굴참나무, 갈참나무 엽(葉)의 광보상점(光補償點)은 각각 18, 20, 24, $38{\mu}Em^{-2}S^{-1}$ 였으며, 광포화점(光飽和點)은 갈참나무 엽(葉)을 제외한 3수종(樹種)에서 약 $500{\mu}Em^{-2}{\cdot}s^{-1}$였다. 2. 갈참나무, 신갈나무, 졸참나무, 굴참나무 엽(葉)의 최대(最大) 순광합성속도(純光合成速度)는 각각 11.0, 11.2, 15.2, 19.7 mg $CO_2dm^{-2}h^{-1}$였다. 3. 굴참나무와 졸참나무엽(葉)의 기공증산속도(氣孔蒸散速度)는 신갈나무와 갈참나무엽(葉)보다 높았으며 각피증산속도(角皮蒸散速度)는 4수종(樹種)모두 비슷하였다. 4. 최적광합성(最適光合成) 온도(溫度)는 신갈나무엽(葉)에서는 약$20^{\circ}C$, 갈참나무, 굴참나우, 졸참나무엽(葉)에서는 약$25^{\circ}C$ 였으며, 4수종(樹種)모두 약 $40^{\circ}C$에서 순광합성속도(純光合成速度)가 0에 달했다. 5. 엽(葉)의 암호흡속도(暗呼吸速度)의 크기는 굴참나무>신갈나무>갈참나무>졸참나무 순이였다. 6. 엽(葉)의 최대(最大) 생산효율(生産效率)(Pg/Rd)은 졸참나무와 신갈나무는 $20^{\circ}C$, 갈참나무는 $25^{\circ}C$, 굴참나무는 $15^{\circ}C$에서 일어났으며 그 크기는 졸참나무>신갈나무>갈참나무>굴참나무 순이였다. 7. 졸참나무엽(葉)의 순광합성속도(純光合成速度)는 -1.2Mpa에서 초기감소(初期減少)가 시작되어 2.9Mpa에서 0에 달했다. 또 엽(葉)이 3%의 수분손실(水分損失)을 받으면 순광합성속도(純光合成速度)의 초기감소(初期減少)가 시작되어 17.5%의 수분손실(水分損失)에서 0에 달했다. 8. p-v곡선(曲線)에 의해 얻은 수분특성인자(水分特性因子)로 판단(判斷)할때 갈참나무와 굴참나무가 신갈나무와 졸참나무 보다 내건성(耐乾性)이 더 강(强)함을 알 수 있었다.

• 한국산림과학회지
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• 제108권2호
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• pp.139-146
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• 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.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1984년도 학술대회지
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• pp.57-62
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• 1984

4년근 미국 인삼을 재료로 미국 North Carolina 소재 인삼포에서 대조군과 부초처리군으로 나누어 재배 시험을 수행하였다. 토양 산도(pH 4.4, 5.5, 6.5) 토양 인산(19, 89.232 ppm) 및 부초처리 (밀짚, 솔잎, 포프라나무 껍질 소나무 껍질 등을 상면에 피복) 재배가 개별 진세노사이드 함량에 미치는 영향을 조사했다. 각 시험구에서 재배한 인삼옆과 인삼근 조직을 H-PLC를 이용하여 5가지 진세노사이드($Rg_{1}$, Rd. Re, $Rb_{2},\;A_{1}$) 함량을 분석하였다. 각 피복재료중에서 떡갈나무 껍질로 피복 재배한 시험구가 인삼 생육 및 진세노사이드 함량이 전반적으로 좋은 경향을 보였다.

• 한국안전학회지
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• 제24권4호
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• pp.17-21
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• 2009

The fire whirl occurring in the urban and/or wildland fire is generated by the instabilities of atmosphere. The fire whirl is a rare phenomenon, but highly destructive because it has high inhalation and lift force. In this study, experimental study is performed with oriental oak leaves, for investigating of the fire whirl characteristics occurred in wildland fire. As a result of experiment, the circulation intensity increases as increasing of the induced air velocity, and then the fire whirl occurs. Also, the heat release rate and flame height increase 22% and 18% in highest circulation.

• The Korean Journal of Ecology
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• 제1권2호
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• pp.57-65
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• 1977

The biomass and net production of alder and oak trees was estimated by allometric method. The productivity of the two stands of alder and oak was obviously different judging from the rate of photosynthesis productive structure and vertical distribution of light. The amounts of net photosynthesis under the saturated light were 2.31, 1.42mg $CO_2/dm^2\cdot$hr. in the sun and shade leaves of alder tree and 1.58, 0.84mg $CO_2/dm^2\cdot$hr in that of the oak, respectively. Total annual respiration loss calculated from the respiration measured at $25^{\circ}C$ and the mean air temperature from every 10 days were 13.56ton/ha.yr in the alder stand and 19.83 ton/ha.yr in the oak. The productive structure and the vertical distribution of light in the stand were assumedly more effective to produce dry matter in the oak stand than in the alder. The biiomasses measured in 1975 and 1976 were 51.51 and 56.82 ton/ha in the alder stand and 73.35, 86.77 ton/ha in the oak one, respectively. Annual net production and gross production were 8.56 and 22.12 ton/ha.yr in the alder stand but those were 17.90 and 37.74 ton/ha.yr in the oak stand. The ratios of respiration to gross procution (R/Pg) were prespectively 0.61 and 0.53 inthe alder and oak stands. Efficiencies of solar energy utilizaztion of net production during the growing season(May-Oct.) were 0.67 and 1.40% and those of gross production were 1.72 and 2.94% in the alder and oak stands respectively.

• 원예과학기술지
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• 제33권3호
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• pp.309-316
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• 2015

In this experiment, five commercial cultivars and one wild species of loquat were used to investigate frost tolerance and enzymatic activities in leaves and young fruits under cold stress at $-3^{\circ}C$. The frost injury, malondialdehyde (MDA) content, and oxygen-scavenging enzyme activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) were studied. This results showed that the wild species 'Wild Oak-leaf' loquat was the most frost tolerant among accessions tested, followed by the cultivar 'Golden Block'. Other cultivars, 'Wu Gong Bai', 'Taicheng 4', 'Xiangzhong 11' and 'Zaozhong 6', were relatively weak in frost tolerance. The enzymatic activities of SOD, POD and CAT increased initially and then decreased as the exposure time increased. However, the enzymatic peak occurred later in the frost-tolerant accession than in the frost-sensitive accession. The correlation coefficients of MDA contents between leaves and immature fruits were from 0.93 to 0.99 in the five commercial loquat cultivars. For the 'Wild Oak-leaf' loquat, the correlation coefficients of MDA and POD were 0.98 and 0.95, respectively, but the coefficients for SOD, CAT and APX were relatively low. In general, there were good correlations between loquat leaves and immature fruits in MDA content and enzyme activities. These results indicate that analysis of these physiological and biochemical activities in loquat leaves could potentially be used to predict the cold tolerance in loquat at immature fruit stage and to accelerate breeding programs for cold tolerance in loquat.

• 한국자원식물학회지
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• 제23권3호
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• pp.242-247
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• 2010

This study was carried out to elucidate the effect of mulching materials on the growth of Chinese chive (Allium tuberusum Rottler) and weed control. Chinese chive was grown under five mulching materials, pine leaf, oak leaf, rice straw, rice hull and sawdust, at the Experimental Farm of Chungbuk National University from June 20, 2009 to September 30, 2009. Amaranthus mangostunus, Digitaria sanguinalis, Portuclaca. oleracea, Echinochioa crus-galli var. frumetacea and Setaria viridis were dominant weeds. Both pine and oak leaves were significantly effective mulching materials in terms of weed control indices in both nursery and field. Soil moisture contents were 1.2~3.7% higher in mulching, especially in oak leaf mulching. Mulching with pine leaf significantly increased plant height, sheath length, leaf length, bulb-, root- and leaf-weights and yield of Chinese chive, but there were no significant differences among the other mulching materials although better than those in non-mulching.