• Asian-Australasian Journal of Animal Sciences
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• v.22 no.6
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• pp.843-848
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• 2009

This experiment was conducted to compare the effects of oak acorns and corn on broilers growth performance, carcass characteristics and meat fatty acid (FA) composition according to different ages of broilers. Two separate groups of 400 male broilers, reared for six weeks, were fed diets containing 33.5% green oak acorns (GO) and 67% of corn (C), respectively. At day 35, the body weight of the chickens fed the GO diet was 12% lower (p<0.05) compared with controls (C). However, at day 56 birds reached similar final weights. Abdominal adipose tissue (AAT) was 78% higher in the controls compared to those fed the oak acorn-based diet. The total lipids (TL) of thigh muscle were higher in the controls compared to dietary treatment GO (3.1 against 2.5 g/100 g of muscle). There were significant differences in fatty acid (FA) composition of the muscle between two groups. The broilers fed oak acorn exhibited more C18:2, as well as a higher proportion of polyunsaturated fatty acid (PUFA) and PUFA:SFA (saturated fatty acid) ratio than those on the control diet, but no significant differences were observed among groups for the age of birds. There was a higher proportion of linolenic acid in broilers fed the oak acorn compared to the controls (0.8 vs. 0.6%). Furthermore, linolenic acid content decreased with age (p<0.001) in both groups. The results indicated no significant differences in FA with the age of birds. In conclusion, the meat fatty acids provided by the GO diet appeared to improve the nutritional quality preferred by the consumer.

• Journal of Ecology and Environment
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• v.44 no.4
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• pp.229-240
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• 2020

Background: Genus Quercus is a successful group that has occupied the largest area of forest around the world including South Korea. The acorns are an important food source for both wild animals and humans. Although the reproductive characteristics of this genus are highly variable, it had been rarely studied in South Korea. Therefore, in Seoraksan and Odaesan National Parks (i) we measured the acorn production of Quercus mongolica, an overwhelmingly dominant species in South Korea, for 3 years (2017-2019), (ii) evaluated the spatial-temporal variation of acorn production, and (iii) analyzed the effects of oak- and site-related variables on the acorn production. Results: The annual acorn production of Q. mongolica increased 36 times from 1.2 g m-2 in 2017 to 43.2 g m-2 in 2018, and decreased to 16.7 g m-2 in 2019, resulting in an annual coefficient of variation of 104%. The coefficient of spatial variation was high and reached a maximum of 142%, and the tree size was the greatest influencing factor. That is, with an increase in tree size, acorn production increased significantly (2018 F = 16.3, p < 0.001; 2019 F = 8.2, p < 0.01). Elevation and slope also significantly affected the production in 2019. However, since elevation and tree size showed a positive correlation (r = 0.517, p < 0.001), the increase in acorn production with increasing elevation was possibly due to the effect of tree size. The acorn production of Odaesan for 3 years was 2.2 times greater than that of Seoraksan. This was presumed that there are more distribution of thick oak trees and more favorable site conditions such as deep soil A-layer depth, high organic matter, and slower slopes. Conclusion: As reported for other species of the genus Quercus, the acorn production of Q. mongolica showed large spatial and annual variations. The temporal variability was presumed to be a weather-influenced masting, while the spatial variability was mainly caused by oak tree size.

• The Korean Journal of Ecology
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• v.24 no.6
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• pp.377-380
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• 2001

Herbivory is an important selective forces on plants by reducing the ability of the plant to compete with its neighbors and to produce offspring. Oak nut weevil(Mechoris ursulus Roelofs) females lay eggs in unmatured acorns and cut off the branch of oviposited acorns. To investigate the influences of branch-cutting behavior of oak nut weevils on oak production, we surveyed the horizontal and vertical distribution ranges of damaged oaks and depth of sites of overwintering larvae and quantified the amounts of biomass and acorn removed by the weevils on deciduous oak species. All of the endemic oak species in Korea were damaged by oak nut weevils in all of the study sites including Mt. Halla and Mt. Seorak. The upper limit of vertical distribution of damaged oaks by the weevils raried from 700 m to 900 m. Mostly their larvae were found in soil from 8.1 cm to 10.0 cm depth in winter. Percentage of annual net primary productivity($720g{\cdot}m^{-2}{\cdot}day^{-1}$) of oak species removed by the weevils was about 7%, which is higher than the percentage removed by all the herbivores in typical temperate forest(5%) and equivalent to that by all the herbivores in tropical forest. The predation percentage of annual acorn production by oak nut weevil was 27% in Q. mongolica and 33% in Q. acutissima. This results indicate that the branch-cutting behavior of oak nut weevil may be the most important factor regulating oak population and affecting other predators dependent on acorns.

• 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.

• Journal of agriculture & life science
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• v.46 no.4
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• pp.1-8
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• 2012

Acorn production of some oak species from 2008 to 2010 in Mt. Jiri national park(Pia, Bitjeom, Jangdang, Baemsa, Hansin, and Chilsun) was measured and compared among study area, altitude and aspect because acorns are an important wildlife food resources. Acorns were produced the most in Jangdang and Bitjeom area at year of good fruiting, and those of Bitjeom and Hansin area were produced the most at bad fruiting year. In terms of altitudinal characteristics on acorn production, acorn production in 1000 and 900 m was the most at good fruiting year, and 800 and 900 m at bad fruiting year showed the most production of acorn. Throughout the study period, acorn production on southern slopes was larger than that of northern slopes.

• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.126-136
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• 2017

We describe characteristics of diversity and distribution of oak forests on the Daegok-cheon gorge of the Southeastern Korean Peninsula, the oldest prehistoric site, in view of a sort of food resources of acorns. The $Z{\ddot{u}}rich$-Montpellier School's method was adopted for field investigation on the oak dominant stands. A total of 20 phytosociological $relev\acute{e}s$ composed of 193 taxa were analyzed by syntaxonomy and ecological flora. The Daegok-cheon's oak forests occupied 36.9% ($513,374m^2$) of the surveyed area, and its 99% ($507,677m^2$) was Quercus variabilis and Q. serrata stands. Oak forests of the Daegok-cheon gorge are a kind of regional vegetation type characterizing by the high relative net contribution degree (r-NCD) of Platycarya strobilacea and Sapium japonicum, which are an edaphic type of the xerophilous and thermophilic oak forests. The region of the Daegok-cheon petroglyphs is defined as an ecoregion with rich acorn supply and abundant water resources, and the warmer environment, which attracts prehistoric man.

• Journal of Forest and Environmental Science
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• v.32 no.2
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• pp.103-112
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• 2016

To compare seed components of plus trees, seed powder ground after seedcoat removal was analyzed for two oak species, i. e., Quercus monglica (white oak) and Quercus variabilis (red oak), which are typical oak trees in Korea but have different fruiting characteristics. Thus we aimed at analyzing and comparing many ingredients including minerals, sugars, etc. Two species were similar to each other in the content of water, crude ash, crude protein and carbohydrates, but crude lipid content in Q. variabilis was 2.5 times higher than that in Q. mongolica. Crude proteins of Clone 124 was 1.5 times higher than that of Clone 75 in Q. mongolica. Crude lipid content showed the highest value in Clone 0511 of Q. variabilis, and more phosphate and iron was found in Q. monglica than in Q. variabilis. Glucose showed 85.4% and 88.3% on average of the total monosacchrides in two species, and galactose and arabinose were also found. In the content of phosphate, iron, and crude lipid, differences were found between two species and among clones of two species.

• Korean Journal of Plant Resources
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• v.27 no.4
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• pp.279-285
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• 2014

Nutritional composition, including total phenolics, tannins and nutrient components, of acorns of Q. actissima, Q. serrata, Q. variabilis and Q. mongolica were analyzed. Acorns were collected from each tree species, which were grown in a seed orchard. Contents of both total phenolics and tannins in acorns of Q. serrata were higher than those of Q. actissima (p<0.05). Interestingly, Q. serrata contained the highest amount of water soluble tannins (71 mg/g dw) and the lowest levels of water insoluble tannins (8.1 mg/g dw) among 4 oak species, resulting that acorns of Q. serrata had the lowest proportion of insoluble tannins. Among 4 oak species tested, Q. mongolicav acorns contained the highest levels of both total dietary fiber (TDF) and ascorbic acid, while the content of beta-carotene in Q. mongolicav was 52-fold lower than that in Q. variabilis ($520{\mu}g/100g$). Our result showed that nutritional composition of acoms was significantly different between oak species, indicating that tastes or nutritional values might be different as well among major oak species in Korea.

• Journal of Plant Biotechnology
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• v.48 no.1
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• pp.44-53
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• 2021

The present work aims to study the induction of somatic embryogenesis in cork oak (Quercus suber L.) from immature zygotic embryos and young apical leaves obtained from 2-month-old seedlings through acorn germination on sterilized peat. The immature zygotic embryos were grown for 1 month on the mineral solution of MS in the presence of 4.52 µM 2,4-D and 30 g/L sucrose. They were then transferred to the same mineral solution with no added growth regulators. In the third subculture, yellow somatic embryos, characterized by two voluminous cotyledons, were differentiated from the radicle of the immature zygotic embryos. The induction of somatic embryogenesis in young leaves required a series of transfers on different culture media containing 30 g/L sucrose and 100 mg/L myo-inositol. Secondary or recurrent somatic embryogenesis occurred within the immature somatic embryo radicles after 1 month of culture on growth regulator-free medium containing WPM macronutrients, MS micronutrients, and vitamins.

• Journal of Korean Society of Forest Science
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• v.96 no.4
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• pp.432-437
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• 2007

The purpose of this study was to select regional distinctive Non-Timber Forest Products (NTFP) in Gangwon Inland Mountains Area. It was considered as NTFP Pine mushroom, Raw Oak Mushroom, Chestnut, Pinenut, Acorn, Resin, Cultivated Mountain Ginseng, Fernbrake, Chinese bellflower, Lance asiabell, Angelica, Aster scaber, Sap, Wood Vinegar. Regional weight, item weight and forest products quotient were used for the selection of NTFP. Forest products quotient was an application of Location Quotient that is used Input-Output analysis. As a result, Chestnut was selected in Chuncheon. Raw Oak Mushroom was selected in Wonju and Pyeongchang. It was selected Pinenut in Hongcheon, Lance asiabell in Hoengseong and Hwacheon, Acorn in Cheorwon, Aster scaber in Yanggu and Sap in Inje.