• Research in Plant Disease
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• v.28 no.4
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• pp.209-220
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• 2022

Charcoal canker of oak, which has recently increased in southern Iran, could pose a serious threat to the entire forest ecosystem in the near future. In addition, it seems that climate change and its consequences, such as drought in the southern regions of Iran, have exacerbated this phenomenon. Consequently, the objective of this study was to identify the fungal pathogens that could cause charcoal canker disease in the oak forests of South Zagros. It was also sought to find associations between changes in the occurrence/exacerbation of charcoal canker disease under non and intense drought stress in non-inoculated or inoculated Quercus brantii seedlings. In total, 120 isolates were obtained from eight oak forests located in the Zagros Mountains of Southern Iran, Kohgiluyeh & Boyer-Ahmad and Fars provinces, which were classified as Biscogniauxia mediterranea based on morphological assessment. Subsequently, molecular assay confirmed the result by phylogenetic inference of internal transcribed spacer-rDNA regions, α-actin, and β-tubulin genes. The results of the pathogenicity test showed that the response of isolates of B. mediterranea (Iran-G1 and Iran-M70) was varied in different environments for the measured necrotic lesion length. In comparison with the control moisture treatments (non-stress), the necrotic lesion length in inoculated treatments increased under intense drought stress. In general, inoculated oak seedlings' exposure to water-deficient stress by the pathogen of B. mediterranea could affect the spread/severity of the charcoal canker disease.

• Journal of Korean Society of Forest Science
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• v.105 no.2
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• pp.157-166
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• 2016

This study was carried out to classify the current forest cover types and to propose the successional trends in the natural forest of Mt. Deogyu. The vegetation data were collected by the point-centered quarter method. The forest cover types were classified by various multivariate statistical analysis methods such as cluster analysis, indicator species analysis and multiple discriminant analysis. This forests were classified into five forest types by the species composition of upper layer and topographic positions: Quercus mongolica forest in the ridge, Fraxinus mandushurica-F. rhynchophylla-Cornus controversa forest and F. mandushurica forest in the valley, the Q. serrata - Pinus densiflora - Q. mongolica forest and P. densiflora forest in the low-slope. As a result of the forest successional trends depending on ecological and environmental characteristics in each forest type, the current forest types were expected that the forest succession would be proceeded toward Q. mongolica forest, F. mandshurica forest, mixed mesophytic forest, and oak-Carpinus laxiflora forest.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.1
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• pp.61-70
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• 2007

This study was conducted to investigate nutrient dynamics and water quantity of throughfall and stemflow in natural oak stands in Korea. The ratio of the total throughfnll and stemflow to the amount of precipitation varied with locations. It was considered that the ratio was affected not only by the characteristics of tree species but also by regional, weather and other environmental conditions. It was, therefore, necessary to set up a water control system to launch a tending project for natural oak stands. Comparisons of nutrient amount in throughfall among regions reflected regional characteristics. $Ca^{2+},\;Mg^{2+}$ and $K^+$ ions were leached from the canopy and yellow sand accumulation. $Na^+$ and $Cl^-$ were marine-borne. $NO_3^-$ and $SO_4^{2-}$ resulted from dry deposition of air pollutants. Nutrient amount in the stemflow was as low as about 10% of that in the total throughfall and stemflow. The pH of stemflow in natural oak stands in urban areas ranged from 3 to 5. Influx of the acidic stemflow to soil could, in the long term, affect pH in soil solution and nutrient dynamics around root zones.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.8-16
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• 2002

This study was performed to produce the high reactive lignin zero substrates from autohydrolyzed wood resources. In chemical compositions of used raw-materials, there were significant differences between two species, Japanese larch (Larix leptolepis) and oak (Quercus mongolica) woods. Japanese larch contained 25 to 3.5 times higher amounts of extractives than oak wood, which is mainly derived from high content of arabinogalactan in Japanese larch wood. Oak wood has 5% lower lignin content and 3% higher holocellulose and pentosans than larch wood. Concerned to changes in wood components during autohydrolysis pretreatment at 22 kg/cm² steaming pressure for 5~60 min, glucose content was constant during pretreatment, while hemicellulose and lignin were abruptly changed. Hemicellulose fraction was decreased significantly and lignin contents increased because of its condensation reaction with hemicellulose degradation products. The pH of hydrolyzates during pretreatment was decreased, reached upto pH 3 and since then leveled off. In the case of oak wood, same tendency was observed as in Japanese larch. Autohydrolysis followed by sodium chlorite and sulfite or bisulfite pretreatment was very effective in delignification of the substrates. In particular, two-stage delignification of autohydrolyzed woods with alkali and O₂-alkali resulted in very low lignin content substrates, such as 0~0.2% lignin substrate.

• Korean Journal of Environment and Ecology
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• v.24 no.5
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• pp.539-546
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• 2010

To investigate the variation of anion concentrations in relation to forest type, forest-related factors, forest survey and anion concentrations measurement were carried out on the 52 quadrats located at the national forest areas in Yangyang-gun, Kangwon-do. The relationship between anion concentrations and forest-related factors were correlated. Total mean of anion concentration was 2,405 ea/$cm^3$, which was slightly higher than general figures 2,000ea/$cm^3$. Highly significant positive correlations were observed between anion concentrations and soil moisture contents, and also between anion concentrations and altitude. Significant positive correlations were observed between anion concentrations and topography. Anion concentrations were significantly different among soil moisture levels. Mean anion concentration were highest at 4,524.4ea/$cm^3$ in on wet sites, and followed slightly wet sites and moderate sites. Mean anion concentrations was highest on valley sites at 3,372.4ea/$cm^3$, followed by slope and ridge areas. Mean anion concentrations measured before noon was highest at 3,133.4ea/$cm^3$, and measurements during 12:00~15:00 and after 15:00, showed relatively low anion concentrations. Mean anion concentrations was highest at mixed deciduous forests at 3,503.9ea/$cm^3$, followed by oak forests, pine forests, and pine-oak forests. Results of this study are expected to be used in planning therapeutic forests.

• Journal of Korean Society of Forest Science
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• v.86 no.3
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• pp.391-398
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• 1997

Present study describes a method on the application of efficient tissue culture systems for the micro-propagation of juvenile and mature sawtooth oak(Quercus acutissima). Nodal segments with axillary buds were used as initial explant sources. WPM(Woody Plant Medium) was the best in growth and proliferation of shoot among the media tested. Although the single effect of zeatin revealed on two dorminant shoot elongation with normal growth until the elevation of levels up to 3.0mg/l, BAP($N^6$-benzyl amino purine) usually showed better response than zeatin on shoot multiplication and/or elongation. In addition, the incorporation of BAP and zeatin onto the culture media represents more effectiveness in shoot proliferation and its growth. Optimum concentrations of BAP and zeatin were 0.5 and 0.05~1.0mg/l, respectively. Ninety percent of the proliferated shoots was rooted on half-strength GD (Gresshoff and Doy, 1972) medium containing 0.5mg/l IBA(indole butyric acid) in 4 weeks after culture. More than 70% of the rooted plantlets survived after 5 months of transplanting into artificial soil mix containing equal amount of peatmoss and perlite. Among 27 plus tree clones which were grafted twice onto the juvenile rootstocks, only 4 clones revealed the possibility for shoot multiplication through tissue culture system. The capacity for the micropropagation using mature explant sources was highly depended on clonal differences compared with those of octet age. More than 90% of rooting ratio was obtained from the best responding clone. Among the 7 rooting media tested, GD medium was the best far rooting. The most effective rooting was obtained on half-strength GD medium containing 0.2 to 2.0mg/l IBA. More than 60% of rooted plantlets survived after 5 months of transplanting into the artificial soil mix.

• The Korean Journal of Mycology
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• v.45 no.2
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• pp.121-131
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• 2017

We evaluated the antioxidant properties of Lentinula edodes upon sawdust bag cultivation with 5 oak substrates: Quercus acutissima, Q. mongolica, Q. serrata, Q. aliena, and Q. variabilis. We found that the optimal extraction conditions were 70% (v/v) methanol shaken at 150 rpm at $25^{\circ}C$ and 150 rpm for 24 h. The methanolic extracts from L. edodes contained high phenolic and flavonoid contents, they also exhibited stronger antioxidant activities. The total phenolic contents and total flavonoid contents of the mushroom extracts ranged from 2.37 to 3.12 milligrams of gallic acid equivalents per gram of dried mushroom (mg GAE/g) and 0.48 to 0.48 milligrams of quercetin equivalents per gram of dried mushroom (mg QE/g), respectively. In addition, the mushroom extracts exhibited 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (15.8% to 89.4%) at 2 to 10 mg/mL, ferric reducing antioxidant power (0.153 to 0.425) at 5 to 20 mg/mL, and reducing power (0.078 to 0.359) at 5 to 20 mg/mL, respectively. Q. aliena more effectively increased total phenolic contents, total flavonoid contents, and antioxidant activities than the other oak substrates.

• Korean Journal of Environment and Ecology
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• v.23 no.4
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• pp.333-345
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• 2009

Carpinus laxiflora communities are known as the climax forest community of the temperate zone of Korea. There are three Carpinus laxiflora communities in Seoul. The purpose of this research is to analyze the characteristics of Carpinus laxiflora communities of Seoul and supply basic data for establishing of a management plan. The research sites are Sahmyook University, Mountain Dobong and Jinkwandong. This study considers investigation and the analysis of communities structure, soil characteristics and the growth increment of trees. As the result of study, we could know that the growth increment of the Carpinus laxiflora trees of Seoul is decreasing recently because of soil acidification and so on. Also the vegetation disturbance is increasing because of naturalized plant. Oak wilt disease has appeared in the oak forest around Sahmyook University that is the largest Carpinus laxiflora communities area in Seoul. For that reason the open gap was appeared in forest, and the spread of naturalized plants has been increasing in the gap. Furthermore, the Carpinus laxiflora trees are affected by the Platypus koryoensis which is a kind of oak wilt disease. And so, Unless there is a specific management plan, the survival of Carpinus laxiflora communities are uncertain in Seoul. Therefore the management plan of Carpinus laxiflora communities is necessary such as precise investigation, annual monitoring, etc. For the conservation of the Carpinus laxiflora communities, it is necessary to establish the management plan of the biodiversity for Seoul area.

• Journal of Mushroom
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• v.5 no.3_4
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• pp.91-97
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• 2007

Shiitake mushroom (Lentinula edodes) is usually cultivated on the oak log. Log cultivation of this mushroom is getting difficult to get oak logs and has a weak point of its long cultivation period. Recently sawdust cultivation is getting increase. It is important to make mycelia browning on the substrate surface. This browned surface in sawdust cultivation plays an important role like as artificial bark of the oak log, which protects the other pests and suppresses water evaporation in the substrate. The period for mycelia browning is so long that the sawdust cultivation of Shiitake mushroom can not spread well into the mushroom farms. The development of methods for the rapid mycelia browning is quite required. In this article we would like to discuss about the enzymatic activities related mycelia browning and search the methods of cultivation period reduction.

• Journal of Ecology and Environment
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• v.35 no.3
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• pp.227-234
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• 2012

Quercus aliena and Q. serrata are both occur as natural vegetation alongside natural freshwater bodies of the southern Korea Peninsula. Q. serrata dominates over Q. aliena as secondary forest vegetation in the present day. In order to explain these natural distributional traits of the oak species, we conducted some experiments with oak seedlings which treated with major important environmental resources, including light, moisture and nutrients, under controlled conditions. We then measured the ecological niche breadths and overlap from 15 eco-morphological characteristics. The ecological niche breadth of Q. aliena and Q. serrata were higher in terms of the nutrient factor applied, but was lower terms of light. The niche breadth of Q. serrata was wider than that of Q. aliena in light and moisture exposure. On the other hand, the niche breadth of Q. aliena was similar with that of Q. serrata in terms of the nutrient factor applied. These results imply that Q. serrata has a broader ecological distribution in over a wider variety of light and moisture environments than that of Q. alien. Ecological niche overlap between two oak species was the widest in terms of the light treatment factor applied, and narrowest in terms of moisture. This response pattern was also verified by cluster and principle component analysis. These results suggest competitive interactions between Q. serrata and Q. aliena seedlings may be higher for light resources than moisture or nutrient resources, and that Q. serrata is more shade tolerant than Q. aliena.