• The Plant Pathology Journal
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• 제35권6호
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• pp.674-683
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• 2019

Some species of the Trichoderma genus are reported as the major problem in oak wood mushroom production in Korea. In spite of economic loss by the fungi, scientific information on airborne Trichoderma species is not much available. To generate information for disease management development we analyzed airborne Trichoderma. A total of 1,063 fungal isolates were purely obtained from indoor air sampling of cultivation houses used for oak wood mushroom using sawdust media. Among the obtained isolates, 248 isolates were identified as Trichoderma fungi including T. harzianum, T. atroviride, T. citrinoviride, and T. pseudokoningii, by morphological and molecular analysis. T. harzianum was dominant among the four identified species. All the four Trichoderma species grew fast on solid nutrient media tested (potato dextrose agar [PDA], malt extract agar [MEA], Czapek's Dox + yeast extract agar [CYA] and cornmeal dextrose agar). Compact mycelia growth and mass spore production were better on PDA and CYA. In addition, T. harzianum and T. citrinoviride formed greenish and yellowish mycelium and spores on PDA and CYA. Greenish and yellowish pigment was saturated into PDA only by T. pseudokoningii. These four Trichoderma species could produce extracellular enzymes of sawdust substrate degradation such as β-glucosidase, avicelase, CM-cellulase, amylase, pectinase, xylanase, and protease. Their mycelia inhibited the growth of oak wood mushroom mycelia of two tested cultivars on dual culture assay. Among of eleven antifungal agents tested, benomyl was the best to inhibit the growth of the four Trichoderma species. Our results demonstrate that the airborne Trichoderma fungi need to be properly managed in the cultivation houses for safe mushroom production.

• International Journal of Industrial Entomology and Biomaterials
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• 제7권1호
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• pp.75-78
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• 2003

This study was carried out to investigate the mineral content of the feces of the $5^th$ instar larvae in a few silkworm species such as a parent domestic silkworm (Jam134), a hybrid (Kumok-jam), the Japanese oak silkworm, and the Chinese oak silkworm. The major minerals of all silkworms throughout all $5^th$ instar larval period are K, P, Mg and Ca, and the result is consistent with the previous study of the mineral content in the mulberry leaves. Although the calcium content decreased sharply at $7^th$ day of the $5^th$ instar, the crude protein content significantly increased at the same age in both domestic silkworms, suggesting a direct relationship between feeding behavior of the silkworms at the larval period and mineral/protein contents. However, this trend was not observed in both oak silkworms. In the comparison of the mineral content among silkworm species, two domestic silkworms were significantly higher in the calcium content compared with two oak silkworms, and the hybrid Kumok-jam was further higher significantly than the feces of parental Jam 143. Excluding the calcium content, overall no significant content variation in other minerals was observed among four silkworm species studied in this study.

• 한국대기환경학회지
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• 제20권1호
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• pp.111-118
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• 2004

In order to compare the NVOC (Natural Volatile Organic Compound) emission rates from oak trees, the emission rates of isoprene were quantitatively measured in situ based on tree species and region. As a result, the emission rates from Quercus serrata T. were found to be 1000 times greate. than those from Quercus acutissima C. However, the emission rates at the Chili and Gumsung mountain sites did not show any significant differences in summer. Cuvette tests using four different oak species also supported that there was a tremendous difference in emission rates between Quercus serrata T. and Quercus acutissima C. It was found that the emission rates from the trees were highest on the order of Quercus serrata T., Quercus aliena B., Quercus acutissima C. and Quercus variabilis B.

• Journal of Forest and Environmental Science
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• 제34권4호
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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.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• 제18권9호
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• pp.1262-1266
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• 2005

Twelve Korean native goats, spontaneously infected with mixed species of Eimeria were used to study the possible direct anticoccidial effect of feeding condensed tannin-containing plants on the production of Eimeria oocysts. The effects of feeding pine (Pinus densifora) needles, oak (Quercus acutissima) leaves and lucerne chaff on coccidia oocyst output were studied for a period of 10 days post-feeding. The results indicate that feeding fresh pine needles (40 g condensed tannins (CT) dry matter (DM)/day/goat) and oak leaves (40 g CT DM/day/goat) in combination with lucerne chaff had rapid anticoccidial activities in goats as demonstrated by a sharp decrease in oocyst production. Two days after feeding, the numbers of oocysts per gram of faeces (OPG) from the goats fed pine needles with lucerne chaff, and from goats fed oak leaves reduced by 40% and 44% compared to pre-feeding, respectively. On the sixth day after commencing feeding pine needles and oak leaves, the reduction was 81% and 72%, respectively. Ten days after feeding pine needles and oak leaves, the OPG was reduced by 93% and 85%, respectively compared to pre-feeding. Statistical analysis showed that feeding pine needles and oak leaves to goats naturally infected with coccidia significantly (p<0.001) reduced the numbers of oocysts compared to the control group fed lucerne chaff only. Four clinically important species of coccidia, Eimeria parva, Eimeria ninakohlyakimovae, Eimeria christenseni and Eimeria arloingi were identified in Korean native goats.

• 한국농림기상학회지
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• 제10권4호
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• pp.141-148
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• 2008

피음처리에 의한 네 참나무 수종(신갈나무, 졸참나무, 상수리나무, 굴참나무)의 광합성 반응 특성을 조사하기 위하여, 차광막으로 전천광을 35%, 55%. 75% 차광 처리한 조건과 전광조건에서 엽생장과 엽록소함량을 측정하고 광-반응 곡선과 A-Ci 곡선을 통하여 광합성계의 특성을 조사하였다. 그 결과, 굴참나무와 상수리나무는 엽생장, 엽록소함량, 순양자수율을 증가시키고 엽록소 a/b와 탄소고정효율을 감소시켜 빛의 흡수량과 광합성에 대한 이용효율을 높이는 적응 반응을 나타냈다. 신갈나무는 굴참나무와 상수리나무와 같은 경향의 적응반응을 보였지만 광합성 광화학계 활성의 저하로 낮은 광합성 능력을 나타냈다. 졸참나무는 가장 낮은 내음성 적응반응을 나타냈다.

• Journal of Plant Biology
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• 제31권1호
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• pp.33-39
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• 1988

The environmental gradient analyses were aplied for the ordination of forest vegetation in Mt. Naejang national park area in Korea. The species population sequence along soil moisture gradient, mesic to xeric, was shown in following order: Zelkova serrata, Celtis sinensis, Lindera erythrocarpa, Cornus controversa, Acer mono, Carpinus tschonoskii, Quercus aliena, Daphniphyllum macropodum, Torreya mucifera, Carpinus laxiflora, Quercus serrata, Quercus variabilis, Quercus mongolica and Pinus densiflora in tree species and Acer pseudo-siebolidianum var. koreanum, Lindera obtusiloba, Styrax obassia, Styrax japonica, Acer pseudo-sieboldianum and Rhododendron schlippenbachii in shrub species. Ten ecological groups of tree were grouped and coincided with the vegetational units in phytosociological classification by Z-M method, associations. Four vegetation types, cove forest with Zelkova serrata and Lindera erythrocarpa, hornbeam forest with Carpinum laxiflora and Carpinum tschonoskii, oak forest with Quercus variabilis and Quercus mongolica and pine forest with Pinus densiflora as the dominant species were separated in mosaic chart by the two dimensional analyses of elevation and soil moisture gradient.

• 한국안전학회지
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• 제22권6호
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• pp.46-54
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• 2007

The purpose of this study was to examines the burning rate of fire retardant treated wood in the cone heater with a one-dimensional integral model. The wood samples used in this study were four species. The species of woods are Redwood, White oak, Douglas fir and Maple. Each sample was nominally 50mm thick and 100mm square. Samples were exposed to a range of incident heat fluxes 10 to $35kW/m^2$ using the cone heater. A one-dimension integral model has been used to predict burning rate, heat of gasification, flame heat fluxes, charring rate and char depth of samples. As a result measurement of mass loss rate, softwoods(Redwood and Douglas fir) has relatively low value than those for hardwoods(White oak and Maple). Average charring rate of woods in case of fire retardant treatment showed reduction effect of 41.29%, 50.00%, 48.18% and 60.82% for Redwood, Douglas fir, White fir and Maple, respectively. Almost all the predictions from integral model showed faster charring than those measured. Average difference between predictions and experimental data was 16%, 9.5% and 11.8% for N, F1 and F2 respectively. Water-soluble fire retardant used in this study find out more effect in hardwood than softwood from the result of measurement of mass loss rate and average charring rate.

• 한국환경복원기술학회지
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• 제13권3호
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• pp.36-45
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• 2010

To analyze the relationship between climatic factors (monthly mean temperature and total precipitation) and tree-ring growths of Quercus mongolica Fischer (Mongolian oak) with different topographic sites in Mt. Worak, more than 10 trees were selected from each of seven stands. Two cores from each tree were measured for ring width. After crossdating, each ring-width series was double standardized by fitting first a negative exponential or straight regression line and secondly a 60-year cubic spline. Seven stands were categorized in two groups using cluster analysis for tree-ring index patterns. Cluster I (four stands) was located in higher elevation (550-812 m) with aspects of east, west and northwest, and cluster II (three stands) was located in rather lower election (330-628 m) with aspects of north and northwest. The aspects of two clusters were not significantly different. Response-function analysis showed a significant positive response to March precipitation for both clusters. It indicates that moisture supply during early spring season is important to radial growth because the cambial growths of ring-porous species, such as Mongolian oak, start before leaf growth. Cluster II showed a positive response to the precipitation of middle and late growing season, too.